Software Alternatives for massive privacy

Operating systems Use GNU/Linux or a *BSD variant. Avoid Windows at all cost and preferably also avoid macOS. If you want a 100% free system check out the FSF endorsed distributions

Don't use one, instead use Tor or I2P, if thats not an option; IVPN, OVPN or Mullvad VPN preferably via Monero or cash

Modern browsers
If you like Firefox switch to LibreWolf or use a custom user.js, if you like Chrome switch to Ungoogled Chromium, if you want something minimal with Vim keybinds use qutebrowser. I've used all three, and can't recommend one specifically.

Messaging services
If you want something modern with multimedia, screenshare VC and encryption use Matrix with the Element client, if you don't like electron use nheko. You could also use irc/xmpp.

Search engines
I personally use LibreY (instance). Wiby is also very cool.

Git hosts
If you want to self host use cgit. Otherwise everything isn't great, Disroot looks promising.

Code editors
I personally use Neovim. If you need a GUI, I'd recommend VS Codium (libre VSCode).
Note: I personally use Gentoo GNU/Linux and macOS, Tor, Ungoogled Chromium, Matrix, LibreY, GitHub and Neovim.