Obviously it’s not smart to switch to a Cloudflare-plagued network like that of Matrix if your goal is to escape US tech giants. For strictly internal use on self-hosted instances, sure. But as soon as a matrix room becomes open public Cloudflare rears its ugly head.
Zulip and SimpleX are probably better options. Certainly IRC is a better option so long as the channel has no Matrix gateway. SimpleX is also free of Cloudflare.