I will say, as a vaguely interested outsider (but not so invested in the premise of decentralization that I am going to jump through hoops to use matrix) my impression of the user story "Ok I guess I'll finally check out that matrix thing and see what it's like" was that it assumed I had an understanding of various matrix concepts while getting started, and didn't really guide me down a happy path towards opening a functioning matrix client.
Eg here https://matrix.org/try-matrix/. I suspect 90-99% of first time users would want to just go straight to https://app.element.io/ but instead I had to figure out what the distinction between clients/servers/auth really meant, click through to install element, then select the rightmost icon to open it in my browser.
Some of the docs are similar (https://matrix.org/docs/chat_basics/matrix-for-im/#creating-...) - most likely I just want to make an account for the first time but the content is covering a ton of ground and arguably even introducing complexity (I can use any provider, but I don't have to, but need to keep in mind how it impacts data migrations, anyway this is the company behind matrix, they have an app, go here).
The subtext I sensed when I went through this for the first time was not exactly just that Matrix was complex. It was that the culture/expectations set by the people behind it was using it required me to learn/account for all this stuff even though I just want to open your chat app. To a certain extent as a nerd I am interested in your app, and I know a lot of the existing community is very interested in the technical details. But ultimately I'm just trying to check out a chat app, in fact I have already made the decision to go open it, and all the focus seems to be on selling its configurability/flexibility/potential rather than helping me chat.