pse: thanks all AP a lot for suggestions :)
We use Google Calendar for stuff at work, Google still has an old psuedo-deprecated-not-talked-about CalDav endpoint I hit with DavDroid that gives me all of that. These problems were solved with protocols long before gardens. I use offlineCalendar(Yes you need an app for that in Android) to create a calendar for myself locally, though I have a radiCAL server for things I need sync'd. Could have used Fastmail I guess.
The only thing I'm still missing is public transit navigation.
I do have the Play Store installed though - through OpenGApps pico - I only have the Play Store, none of the other Google stuff - with a dummy gmail account.
I don't know gphotos and I don't really watch or show my photos on my phone.
How do you get apps?
I use raccoon to download from GPlay if I need to as a peer stated and know when to update with apktrack from fdroid, but really that's only for Slack since we use it at work. Slack uses Google Push Notifications like most apps, so it doesn't notify me about updates, but I check it periodically enough. I could go the microG route, but I prefer not having to interface with google servers at all if possible.
Edit: Maybe I can either convince my work to use something like Riot.im when it gets mature enough, or use a slack bridge for it and rid myself of this problem.