To be fair Matrix does lack a lot of features still. Video and voice calls are a mess, there's not the equivelent of voice channels afawk.
For those of us who are plural, there's no plural kit alternative (at least not widely avaliable), the moderation tools and permissions systems are a joke (we should know we used to moderate a whole server and several spaces). The search is really bad or non existent in several clients.
A lot of this is because those behind matrix are more concerned with corporations and their needs than the common user, and keep making really ridiculous and assinine decisions; like keeping matrix.org as open signups until it becomes too big to moderate and they have to start charging people for the privelege of decent performance, instead of what they should have done a long time ago and shutting their doors so as to encourage federation.
Matrix is actually not at all well thought through or accessible, we have never and will never use discord, but we can't deny they have a point.