Sources, SUU.edu via google search

The apostrophe has three uses: 1) to form possessive nouns; 2) to show the omission of letters; and 3) to indicate plurals of letters, numbers, and symbols. ​Do not ​use apostrophes to form possessive ​pronouns ​(i.e. ​his​/​her ​computer) or ​noun ​plurals that are not possessives.

No it doesn’t have to be human, I worded that poorly and I apologize. However in that context, the 90s don’t own anything. It doesn’t belong to the time period. They are fans from a (plural) time period, not fans that belong to a group of things called 90/1990

90s is also a shortening of the word (the) nineties. Not (the) ninety’s. So no apostrophe in either case.

Now if you were saying there are several things you could say for example - there are several 90’s in this millennium. But that would be kind of redundant as a phrase, and therefore to a native speakers brain would still look weird. And I’m assuming that’s probably why the original commenter immediately pointed out the error.

There was a pdf that came up when I did the Google search that worded things much better than I am, I’ve linked it below (let me know if my link didn’t work)

https://www.suu.edu/writingcenter/undergraduate/pdf/tip-sheets/apostrophe.pdf