IMVHO you should not look at "alternatives" in the sense of "substitute a WebApp with another" but in workflow terms:
- emails? They are normally valuable tool and personal stuff, they must not be outside your control as much as possible so GMail or Proton change nothing if you use them with their webmail. Just buy a domain, choose a hosted mail service, just because host one yourself is not that easy these days, sync or better grab your remote inbox to a homeserver and use your mail locally in your desktop. The local part means sync against your server the entire maildir, use a local MUA, with good search, tagging etc capabilities, my personal choice is notmuch, to sync mail muchsync, to grab mail fetchmail+MailDrop (but you might like OfflineIMAP or MBSync). Webmail served by your homeserver (i.e. MailPie or Modoboa or even the simple RoundCube) as a last resort if you aren't at your desktop;
- calendar/agenda? Similarly, personally I use org-mode, far more powerful than modern calendar, but again you might prefer different things, thou local and synced not centrally served.
- Drive? To share files there are various options from classic WebDAV to third party services no reason to be tied to one in particular if that's not yours, the rest of Drive is not really a thing IMVHO
- search? Just use Google Search is not more evil than any other player, there is no real open choice there, YaCy while have a public distributed network count just too few participants to be an alternative and the web is the web, you can't run your own.
- Maps? Again not much real alternatives, a PND is good enough for car navigation, for the rest there are very few other maps services but none as powerful as Maps just due to the scale. OSM is hyper-good in limited areas, very lacking elsewhere so not a real option.
- notes? The best I know are again Emacs/org-mode/org-roam etc combo, TiddlyWiki with a daemon to serve it might be another option, Zim another more limited but still light and classic for certain users.
Looking for alternatives in terms of substituting a player with another is a game loosed from start and does not solve anything: companies are not "good" or "evil" they just follow their interest, some might be less friendly then others, but interests in the game remain the same.