As it's not there yet, it's not a solution for my requirement.
Eventually, maybe.
For now, I think using Matrix to bridge to every other service is quite daunting. Consider these instructions which seem to be needed to connect to a Telegram group:
https://wiki.calculate-linux.org/matrix_telegram_bridge
I'm lucky that I can easily follow those instructions if I want. But to do all that just for 1 group?
The next one uses Slack.
Then Mattermost.
Then Discord.
Then IRC/Freenode.
My client uses MSN.
My other client uses Yahoo.
My other other client uses Skype.
A recruiter contacts me through WhatsApp, when I didn't have installed.
Another contacts me through LinkedIn.
Another through Telegram.
A friend sent me a message over Facebook Messenger. Of course I didn't get the Facebook message for 6 months due to not logging in :-)
(A friend of mine received a message over WhatsApp and didn't know for 12 months because of not having it installed at all, only to find someone they thought had stopped talking to them was actually sending WhatsApp messages, assuming of course everyone uses it.)
And then there are those group chats on Zoom sometimes.
I haven't listed them all...
Matrix has a long way to go before it's reasonably low effort to use seamless integration with all contact points that are coming up in practice.
I looked at Matrix recently, and it's very impressive how much has been implemented!
I'm almost certainly going to start using Matrix soon, if only because some communities I want to follow are on matrix.org itself.
But seamless, easy, and confident integration with many third party channels seems like it may be a long way off. (I'd also worry about messages getting lost or something due to services not integrating well with third party clients, especially given the adversarial relationship some services have.)
The problem is that everything and its pets seem to be using different services, and some of those want to live in walled gardens.
Amidst this, to be honest, I don't even use IM much! I'm not the chatting type.
But for key people or teams I need to use whatever they use, and for community awareness on the internet I want to see conversation where other people are discussing what I'm interested in, and pick up on key items sufficiently close to real-time to participate if I want.