I usually recommend Element X on Android, FluffyChat if they complain too much about Element X after using it a bit, and nheko on desktop.

It is really annoying that Element X is missing so many things Element had (you can't even do /me messages, markdown headlines aren't shown properly either), but getting someone to move apps is pretty tough, so might as well get them on the new one that will hopefully get better with time.

Also I never tell people about voice or video in Matrix unless they ask, and if they do I tell them I don't use it, it's probably not great, and to just use Mumble for voice and Jitsi for video.