We do not apply this kind of logic anywhere else. Lets say for example plants that we eat because they taste good. It doesn't really matter if you can find someone who likes to eat birch wood and says it tastes good, to make the statement "birch wood is tasty" true.

Saying "everyone is beautiful" is like say "everyone smells good". Is simply not true and the rest is just a language trick. It does not mean the same as "everyone smells good to someone". Which would still be a assumption without any proof that is only probably true because of the sheer number of people that exist.

That same train of thought taken to its logical conclusion makes everyone ugly as well.

There are definitely popular preferences. Unfortunately not everyone is born equal. Rejecting reality makes it harder to solve the problems created by it.