The concept is good, but not entirely new.
Session have done this nearly 3 years ago.
And (despite most consider a shitcoin) it runs on the Oxen Network (old Loki) and it's incentivized, as we earn Oxen when running our own Oxen server (local or on service provider)
This server has 3 main services - runs the Oxen Blockchain, runs the Lokinet (onion routing) and Session transmission protocol (no data collected).
Regarding SimpleX, there's "simply" no incentive for proper decentralisation, unlike Session.
So, I'll keep with Session! 😎