Granted it's been a year since I last tried Matrix/Element, but back then it didn't "just work" despite many on HN claiming it did. My experience was far worse than Signal, which honestly I haven't had many problems with and many here claim it doesn't "just work."[0] I hit plenty of bugs in WA too. I think the difference is that I notice the centralized apps fix their bugs faster and that speed is proportional to the size of the parent company. Thing is if it is resolved quickly people just forget the bugs exist (and we also remember bugs more for apps which we haven't been using for long). There's a strong cult like mentality for Matrix, on HN, and I just don't get it (I don't get the cult mentality of Signal either, but HN is fairly anti-Signal so I'm not sure that needs to be addressed but we can). I love the idea of decentralization, but I just haven't seen it pan out and it still looks like it has a long way to go. I hope you all are right, but I'm not going to hold my breath and I don't think "just better marketing" is what's needed. There's a lot more.
[0] Disclaimer, I am still a Signal user because I want to support encryption and privacy and I don't see Matrix there yet and moving ecosystems is difficult. I'll take whatever encrypted and private service I can get friends to use that also doesn't require any tech literacy (this is an extreme must because most of my friends and family don't know a monitor from a desktop).