I just signed up for Matrix because you mentioned it.
I installed the Element front end, because that seems to be the most popular.
It looks like IRC, which is fine if that’s all you need.
It also appears that anything beyond text has to be hotlinked, which is understandable, given that the amount of data transmitted for redundancy between home servers is exponential with the number of home servers.
Really very similar to Lemmy, where the identity of each group is tied to a particular server, e.g. lemmy has !anime@ani.social but Matrix has #anime:matrix.org
So what happens if matrix.org goes away or decides the server admin wants to be hostile to #anime?
The first couple of weeks on a private tracker are always pretty rough, until you can build up your ul/dl ratio high enough to get some breathing room.
Some sites make things easier on newbs than others.
If possible, look for recent freeleech torrents, especially popular ones, download them even if you aren’t really interested in the content, and seed them 24/7 to build your ul stats…