What happens if I am a member of (or host my own) matrix server, and I use it to create an account in one web page; and then later on, that matrix server is del

What happens if I am a member of (or host my own) matrix server, and I use it to create an account in one web page; and then later on, that matrix server is deleted forever. Is there any way I can recover my account? This is why I think I prefer crypto single-sign-on (i.e. ethereum projects that allow this). Because I will always be in possesion of my private key. Is there any equivalent to transfer my account across matrix servers?