If you're happy with those services ... maybe you shouldn't?

I self-host because I prefer to house my data locally when possible. It's easier for backups and I'm not subject to the whims and financial decisions made by a company about whether their service will remain available, what it will cost, what functions it will offer. The tradeoff is work on my part, but I enjoy tinkering and learning.

In my case, I self-host a NextCloud instance for remote access to my docs, a Calibre Web server for eBooks (and to share those with a few trusted friends), a Vaultwarden instance because I'd prefer my vaults not be stored by a company whose servers are likely a major target for bad actors and that could change its TOS or offerings in the future.