Also take a look at the network "protocol": JSON over HTTP longpolling, requiring usually a separate socket for each batch of messages sent or received (unless HTTP/2 is available, then it’s a bit less expensive, still has a massive overhead).

Matrix has so much potential – someday, when it’s built on technologically more ideal foundations.

Python2.7 you’ll barely notice, but the network overhead of the Matrix protocol becomes heavily noticeable by the end user (especially if your cell phone’s data plan runs out, and you’re stuck on 64kbps until the end of the month, then Matrix in larger rooms just becomes impossible)