Kyun is the only server provider that exclusively accepts XMR.
Monero's fungibility enables us to process our own payments, without any third party processors, without KYC, without expensive and privacy-intruding fraud prevention systems.
Not on the website yet, but we are moving away from Revolt (currently revolt is bridged to matrix and vice versa) after some questionable moderation (read "censorship") decisions made by the Revolt moderation team towards other communities. Revolt is open source and can be self hosted but it is not federated like Matrix is.