For non-contemporary movies I trust the Sight&Sound poll [1]. Yes, it's mostly artsy-fartsy movies. I love them.
Sure, that can also be gamed, but very much less so: if you are voting you can pick only your top 10 movies ever, and then the next poll is in ten years. It's very difficult to push marketing on it.
I can of course see two points of failure still:
1. Since it's Sight&Sound who picks the voters, they could choose only voters that fits their "ideology". I don't see what this ideology could be. Also, most directors are very well-known, and they wouldn't vote for Marvel Movie #19 since the votes are public [2].
2. A lot of voters could make a deal among themselves to all pick a certain movie. This is in part mitigated by the large numbers of voters, but of course it can happen.
Paul Schrader gave a lot of shit online because the #1 movie in the 2022 edition was "Jeanne Dielman". He sees that as "Distorted Woke Reappraisal" [3].
I think he's full of shit, and the S&S Poll is the most credible snapshot of (art?) movies made every 10 years.
[1] https://www.bfi.org.uk/sight-and-sound/greatest-films-all-ti...
[2] https://www.bfi.org.uk/sight-and-sound/greatest-films-all-ti...
[3] https://www.indiewire.com/features/general/paul-schrader-sig...
Deadpool scored 85% on rotton tomatoes and that makes sense, it was a bit different than the normal "Marvel" films and was well acted but it is totally not something I would enjoy.
Napolean Dynamite scored 32% and strictly speaking, it was a very oddball film. I really enjoyed it and there are more than enough quotes in it to still make me laugh over 10 years later.
The idea that crowd-sourcing reviews leads to some kind of useful truth is marginal at best but downright wrong.
The problem is curation. I don't want to poll just about anyone. I only want to poll a selected list.
Selected how?
We can go by "seriousness", respect and proven knowledge, like the S&S Poll or the ASC for best cinematography [1].
Or, as you said, trust someone (or a group of people) because I like what they like.
[1] https://theasc.com/news/asc-unveils-list-of-100-milestone-fi...