Matrix is FOSS, Synapse (Matrix server) is FOSS, bridges are FOSS. The only thing stopping most people is a server that can run 24/7

You login to your account with the bridge, so the bridge can pretend to be you.

Half the people here are trying to de-google

You can set up bridges to link to your other messengers. Then you will only need Matrix to be able to reply to everyone.

I setup my own matrix instance and ran a few bridges on it, so I don’t need WhatsApp thanks

I can setup bridges, so I can communicate with any other messaging systems (whatsapp, discord) within matrix