Absolutely agree. We shouldn't add more centralisation.
However, now that WebRTC is widely supported by browsers I believe videochat can be done without the need for centralised high-bandwidth servers.
For decentralised file-storage there are also some interesting projects live already. IPFS (which i think is used by d.tube) or blockchain based like Sia or Burst.
If you ask me, chat messages shouldn't necessarily be stored. It can be session-only or DOM-only. It has its drawbacks UX-wise but I'd consider it safer than permanent chat recording like in Facebook.