It's pretty easy to self-host CalDAV and CardDAV. I went with Baïkal, it took me maybe 15 minutes to install on a server, it's supported by all of the calendar tools I use, and it's worked perfectly fine for a few months now. So now I'm completely free of Google.

Maybe not for everyone, but a way more feasible option than most people seem to realize.

Agreed! I used radicale for the same purpose. Very easy installation given I already had a VPS.

https://radicale.org

Yeah I've investigated it a couple of times but never pulled the trigger with self-hosting. Could run it on my rpi and access via Tailscale, but seems like something that should be provided by the email provider that I pay money for. They also do have Contacts and Calendar products, but they're completely self-contained and apparently can only be used by protonmail which is mostly pointless.

I've been considering switching from Fastmail to Proton for Mail/Calendar/Contacts, but I didn't realize their bridge didn't do CalDAV or CardDAV. Also, apparently the bridge is desktop-only -- no mobile? That's kind of a deal breaker.

Fastmail has mail/calendar/contacts with caldav and carddav support.

What about mobile devices? There is no bridge and you have to rely on official apps, which is the biggest drawback for me.