I just tried to move to Android because it's more open. Was not prepared for the "open" OS to not have basic support for self-hosted calendars. Yes, contacts and calendar are a core OS level feature in 2026.

Yes DAVx5 exists, but Google Calendar was buggy with local calendars and DAVx5 actually didn't work reliably afaict.

Calendar.app is totally seamless with synology on iOS. Same with contacts.

Android was working overtime to make sure I use Google for everything. iOS isn't perfect but I don't have to jump through crazy hoops to be in control of my data.