I think this has two aspects, the superficial and the substantive. The significance of the latter impacts my assessment of the former but to consider the superficial first:
The Title as the time I VTC'd was, as I recall, the rev1 version:
transit visa in london heathrow to Riyadh
but may have been the rev2 version as kindly tidied up by @Ali Awan:
Transit visa in London Heathrow to Riyadh for Filipinos.
It was probably before you added five characters to the body and definitely before you edited the Title 20 minutes later to:
How to enter the UK during a layover as a Filipino citizen?
after you had posted an answer.
It seems that you were correct, it was not a transit visa that was required but an entry visa. So the Q, as asked, was Unclear. This in part because badly presented since a wall of text in poor English and rather arbitrary capitalisation.
Since posted by an unregistered hit-and-run user we have no confirmation that the four edits it has taken to reach its present state (starting as a mere 95 words including Title and tags) is true to the intent.
One answer, in addressing "What visa do we need to be able to tour a bit before our next flight?" does include:
The answer here is indeterminate because we do not have all of the information needed to suggest the best choice. You have two options: Standard Visitor Visa and Transit Visa.
So again, Unclear.
The canonical answer to Is there a way to find out if I need a transit visa for a layover in the UK? does cover the OP's situation, it includes the link behind This UK government site will tell you if you need a visa to transit through the UK. which is (a) still valid and (b) points directly to a page that includes:
Apply for a Visitor in Transit visa if you’ll be going through UK border control but leaving the UK within 48 hours.
So not only is there no evidence of any research effort but indication that they made none.
The third reason for downvoting also applies, it is a duplicate and hence (IMO) not useful.
So OP had the full set of reasons to be downvoted (two or three times over in the case of Unclear).
That though I agree is not the same as reasons to VTC. However Unclear is a VTC reason and was the case when I VTC'd (subsequent editing by others has made some difference).
That's the mess for 'superficial', now for 'substantive':
The Q's tags at present are visas transit lhr filipino-citizens (not the same set as applied by OP). For visas we have 4,068 Qs and with approximations that (a) the All Time 10 Top Answerers for that tag never answered a visas question answered by any other of the Top 10 and (b) none of their answers were to Qs presently Closed, then just those 10 users (out of a base currently reported as 34,438) have between them answered 62% of all visas Qs. That tag happens to be the most used on TSE, applied nearly twice as many times as the next most popular.
I expect such experts' enthusiasm to wane once they have given the same A (to yet another slightly different Q) for the umpteenth time. To an extent they will be replaced by new experts in due course and by established users who know how to copy and paste. Indications from SO however are that quality goes down as volume go up. This I see as a particular risk for TSE because we are a very long way off being the "go to" travel site (eg everybody travels while not all are programmers, yet SO has nearly 200 times as many users as we have) and the very concept is more difficult for a site with a freer format than that imposed by the discipline of code.
I do not dispute that (a) a Q does not have to be identical to a 'master' to count as dupe and (b) a Q that is significantly different from a 'master' is not a dupe even if the 'master' has an answer that suits both.
The problem is with determining what is 'significant'. As far as I am aware there is no general guidance on this anywhere on SO, it is all dealt with case by case.
We can choose to consider each nationality (for example) as 'different' even where nationality makes no difference to an answer, just as we can choose to consider a stay in the Schengen area of 80 days as different from 81 days even when all that matters is that the stay is less than 90 days. And we could choose to combine the two, nationality1 and 80 days different from nationality2 and 80 days different from nationality1 and 81 days different from nationality2 and 81 days. And then we might also choose to consider different where traveling from and by which airline and so forth, again where origin and airline etc make no difference to the answer. Without some degree of generalising answers would in some cases be of no use to anyone but the person asking – a situation that was at one time recognised as undesirable by SE with the "too localised" VTC option.
However if that is our choice it will, in time, drive away our experts and these will not be replaced by similar levels of expertise in proportion to the volumes. IMO this would happen before TSE became the "go to" site and would prevent it from ever becoming the "go to" site.
There is though an alternative, which is to accept we have (a small number of) canonical answers. These may still require a few 'finishing touches' and perhaps will never cover every corner case but where the canonical answer fits the recent Q we agree the recent Q is a dupe.
At present lack of research is clearly seen on TSE as far less of an issue than it is considered elsewhere on SE. But Googling on behalf of those who can't be bothered to do so themselves does not appeal to experts. Within TSE we have text search and tag search and a few users spend considerable effort on the indexing system. We also have vote scores to indicate usefulness. If a user can't find, or cannot be bothered to look for, the canonical the chances of their posting a clear, well-formatted, unambiguous Q with the right tags are slim. It could be edited into shape by others, as long as others have the patience to do so, but all rather pointless and eventually there will not be enough users prepared to do the editing to cope with the requirement for edits (SO is an example).
It is an entirely different matter if the user refers to the canonical and explains in what way their Q is not answered by it.
IMO accepting 'minor' differences as 'significant' jeopardises the future of TSE. If the consensus is to accept 'minor' differences as 'significant' I will "go along with that", at least for the time being, but in my view that is short-termism and why I still think the Q in question should be considered a duplicate.
How much electronics and other valuables can I bring duty-free when going to India? is an example of a Q with a canonical (but, unfortunately, not wiki) A. Dozens of Qs have been closed as dupes of it, though I don't recall any that asked about the exact same mix of quantities (3 of this, 4 of that, 1 of the other, etc, etc, etc) and items (cameras, computers, handbags, ipads, watches, whey powder, etc etc, etc) and departure airport, and arrival airport etc etc etc.
