I myself plan to migrate all of my data to my own services at some point, I already moved away from DropBox to Nextcloud. That could be a good solution to move my family out of the evil gmail, for instance.
Now what I'd like to know is which is better of MailPile, RoundCube, Zimbra, and the many other webmails available...
* https://mailcow.email/ * https://mailinabox.email/
which essentially provide the whole email stack in a relatively nice bundle it seems (I have not yet forced myself to migrate). I think mailpile and roundcube are just the "webmail" part of the stack.
Have it running about half a year and am really happy about it.
If you have the time imho migrating is worth it.
You can transfer your old mails via imap to mailcow, so migrating is easy