I use Fastmail, previously used Proton, Mailbox and Disroot.
I have an email for IRL and one for online as well as some "masked emails" (Fastmail's equivalent of aliasing) for services I don't trust. I'm still transitioning away from Addy for email aliasing.
I currently use Bitwarden although I have been looking into 1Password and KeePass.
Decentralized, Fastmail, Mullvad, Bitwarden and Ente Auth.
Self hosting email is hell from what I've heard and I currently don't have the resources to do that anyways.
Self hosted. It's not that hard, one of those fire and forget services that require 10 minutes a month to support.
Some time ago I've also tried mailu and mailcow instead of doing it by hand, they are cool if a bit opaque.
No, more like using different providers for each service. Bitwarden as a password manager, tuta as an email, filen as cloud etc etc. Putting all eggs in one basket would be using the proton suite for one example, where they provide all of those services at once.