On the one hand I understand the complaints about Apple's "walled garden," but I've pretty effortlessly connected to both Google Calendar and Exchange services. (And I don't use Apple's own Calendar app anyway, although I configure the calendars through the iOS system preferences so they integrate with all the Apple stuff relatively gracefully.) I do file syncing with Dropbox, which integrates with Apple's Files app pretty nicely as of iOS 11. I keep passwords in 1Password, which always integrated fairly well with iOS and does even better as of iOS 12. I get a lot of ebooks in DRM-free ePub format from various vendors and can just open them directly in iBooks. (I suppose using iTunes is still a problem, although iTunes Match and, now, Apple Music actually made syncing pretty painless for me. After the initial pain of moving from iTunes Match, which worked great, to Apple Music, which did...not...work great for its first year. But I digress.)
More apropos to the linked post, I trust Apple with my data rather more than most companies I deal with. They not only don't treat it as a profit center, they seem to prefer to minimize the amount of personally-identifiable and unencrypted information they deal with. I do still use some Google services, but I prefer to use Apple's equivalents when possible -- and I've been using Safari instead of Chrome for years. A lot of people think I'm nuts for that, but occasionally I feel a bit vindicated...
For years I've used an Android phone with no Google account attached - I simply skipped the OOB assistant and then created an account pointing on my company's Exchange, where all my mail/calendaring/contacts were. For maps, I used Sygic, which you can purchase outside Play Store.
Yes, I did lose Google Play, Youtube, Hangouts, but exactly that was the intent - not using Google services. Today, it would be even easier, with the existence F-Droid providing third-party apps.
Had to uninstall DNS66 and F-Droid because of it.
I'm fairly annoyed on Android that I can't uninstall some stock Google apps.
I want to touch on this because in my experience this is less true than it seems on the surface.
The contacts app and calendar app support carddav/caldav respectively- photos use the standard camera interface (mpd?) the things that suck are that you need to use Xcode to develop for it, and you need iTunes to put music on the default music player app (however using plex w/ sync has been my cross platform solution for a while- and honestly I don’t know many people who aren’t using Spotify)
Am I missing something?