I run Strava on my Pixel 10 Pro Fold running GrapheneOS. IIRC you need to have Google Play Store installed (with zero permissions, preferably) to make Strava work.
What's your monthly usage, aprox.? Do you use Kagi for getting to pages you know of but doesn't want to type the whole URL for, eg. typing "Hacker news" in the URL bar instead of "news.ycombinator.com"?
I try to selfhost most of my stuff I rely on. Immich, Vaultwarden, etc. I gave up on trying to selfhost sync solutions for Obsidian - Obsidian Sync is just so damn frictionless compared to all other solutions. Also, it feels good supporting the development of Obsidian.
It works just fine, but every time you open the app you have to dismiss a dialog saying that the app doesn't work without Google Play Services installed.