Modern software deployment methods can fill the gap between your selfhosted need and the work to be done. I won't name technologies here, because existing have its flaws (docker, helm, etc).

Mastodon is federated and thus basically fulfills your whish. IMO "decentralized Web3" such as IPFS may rempve that need for classical "hosts" but at the costs of an entrance barrier for users (have to install that client).