As to whether they need your money or not I’m a bit conflicted. They have raised and spent more and more money every year. They have a lot of money and some have argued they spend it poorly.
On the whole though, besides asking for donations, they have maintained their goal of being ad free. If you’ve ever used a fan wiki for a video game or hobby you have likely experienced how bad a wiki larded down with ads can be.
I think for myself as someone that has worked as a software engineer for my entire life building out massive infrastructure that is on a similar scale to Wikipedia, I don’t really know how they justify such high development spend when the tech isn’t really evolving very much. I’m sure it’s not cheap to host, so that spend is fine by me, but I’m not sure what all they are building. That doesn’t mean it’s not worthwhile, I just have a hard time imagining it.
I would encourage you to look at numbers and decide if they make sense to you. Also people have written on the subject, so some googling will likely bring you to more opinionated pieces than my own.