It sounds most likely the issue wasn't with the client, but with the server. The most popular server matrix.org is dealing with a lot of clients, but its performance has been improved, well, "recently", by improvements to the most popular homeserver Synapse.

The next step plan is to move to Dendrite, which is a new homeserver taking the lessons learned from writing Synapse, as well as being implemented in Go instead of Python. But it doesn't yet do everything. You can try a dendrite-hosted server by using dendrite.matrix.org as your homeserver. (AFAIK it has its own accounts.)