That's just not true. You'll need to give a specific example of which apps are like this on Android. I'm writing this using a LineageOS phone with no proprietary or closed source apps on it right now.
This is true and can be verified by anyone by installing random applications from Google Play Store without having Google Play Services installed. Since relatively recently, you can use some of them via microG, but compatibility varies.
Sure, there's F-Droid and FLOSS software for Android, but if you're already willing to limit yourself to FLOSS Android apps you may very well limit yourself to FLOSS GNU/Linux apps too. When people say "I can't move to Linux phones because I need these Android apps", they usually aren't talking about ones from F-Droid.
You've moved the goalposts. The original claim was that you couldn't run open source android with calendar, email, etc. But that is obviously not true because I'm doing that right now. Now you are pointing at a bunch of closed source software on Google Play, but that's irrelevant to the discussion. And even then you admit it mostly works with the microg compatibility layer. MicroG and WINE are not much different in this respect IMO.
Secondly, you claim limiting yourself to FLOSS android means you might as well just use FLOSS Linux. But that doesn't make sense because the purely open source elements of the android ecosystem work far better than the pure Linux ecosystem, which is my original point. There is no advantage that you can point to for GNU/Linux over Android/Linux other than just being "pure Linux". Android is fully open source and can be easily run unencumbered by proprietary google software. And there is vastly more open source software that is mobile friendly and compatible for Android/Linux than GNU/Linux.
> the purely open source elements of the android ecosystem work far better than the pure Linux ecosystem
This isn't really true, unless you specifically care about compatibility with (1) proprietary Android apps and/or (2) fiddly hardware that's supported in downstream Android builds but lacks complete support on the mainline kernel. Everything else has basically reached and exceeded parity with AOSP. (To be fair, this is a very recent development indeed, and it's quite normal that most would be unaware of it.)
> But that doesn't make sense because the purely open source elements of the android ecosystem work far better than the pure Linux ecosystem, which is my original point.
Do they? I'm using a GNU/Linux phone and I'm happy with it. Of course there are things Android is better at, but that it "works far better" sure isn't something I would say without additional qualifiers.
> There is no advantage that you can point to for GNU/Linux over Android/Linux other than just being "pure Linux".
There sure is. Android ecosystem may be much more mature by now, but it's incredibly hard to hack on. I have recently built a LineageOS image in order to apply bunch of small patches and it took me several hours, 200GB of disk space and couldn't even start building without 16GB of RAM, because the build system was going out-of-memory otherwise. I had to use a VPS because I didn't even have any computer around that I could pull this off on, except of Steam Deck I guess :P In the end, I got two image files that I could flash into the device wholesale that messed up some applications that expected the system to be signed with the same keys as previously.
On my Librem 5, however, I'm able to do `apt source phosh`, `apt build-dep .`, change something and then run `dpkg-buildpackage` to have it recompiled right on the phone itself in a matter of minutes, producing a single deb that I can install and immediately test my changes to whichever system component I want to play with. And if I don't want to hack on the system itself, there's stuff like full blown Python interpreter preinstalled, with bunch of compilers available straight from the repos, for easy scripting and app development right on the device.
If Windows had worked 15-20 years ago when I was still using it like Android does now, I would have never learned the vast majority of what I know about computers now. I gained a lot of knowledge simply by tinkering with my PC, breaking it and learning how to fix it. Being able to patch and change various system stuff by myself was very empowering when I switched to GNU/Linux. These days, most computing happens on mobile phones and tablets with children often completely unfamiliar with common PC workflows that aren't mirrored on mobile; the whole new generation of people, despite of using an OS that's technically Open Source at its core, is mostly deprived from ability to play with their own hardware, and even if they're technically not, the learning curve is often prohibitively high and stuff like SafetyNet still gets in the way - while in my youth I used to learn Python by writing, running and debugging scripts on my Openmoko phone while riding a tram back from school.
Sure, there's F-Droid and FLOSS software for Android, but if you're already willing to limit yourself to FLOSS Android apps you may very well limit yourself to FLOSS GNU/Linux apps too. When people say "I can't move to Linux phones because I need these Android apps", they usually aren't talking about ones from F-Droid.