@daniel Element only develops the Rust and JS SDKs. And the libOLM crypto library of course. All other SDKs are community projects.
On the server side, there is Conduit which forked into conduwuit which forked into Tuwunel which will eventually reach maturity, if the moon is in the right phase. The phone number mapping service is controlled by the foundation. You could use alternative ones or none.
I think Matrix is getting there eventually.