Well you're leaving out a couple of important points. Cobalt's patched Google Play services works great, but is not easy to install for a great many Joe/Jane Average types. And the Android runtime is perma-stuck at what, 4.3?
So the selection of Android titles are indeed diminishing as many drop support for the older version. I had a Z10, Classic, Z30 and Passport SE (still use a Bold 9900 just for fun). I'm a BB ******. But you paint a much brighter picture than reality.
Well that and the amazon app store is not only smaller than the windows store, but of a significantly lower quality. Even if amazon store + BBW was about the same size as the windows store, which I think it would still be short on, bbw is terrible and amazon app store is fairly low grade. Most android app writers use google play services. All the good stuff on android apps is higher than 4.3 and uses play services.
And cobalts apps don't "work great", I mean they are a great enabling software, well written, but its an involved process converting the apps AND many of them don't work.
When I did this, I found about half of the apps didn't convert. And those that did convert, ran slowly, didn't function as well as they do on android (for example could not access SMS messaging) and scaled poorly to the screen ratios of keyboard phones.
I eventually got my mi band paired for example, but it has less functionality on bb10, than in windows 10m. The fellow that's writing the apps for 10m, is working on putting the body of the notifications on the band next - something android has, but bb10 could never have.
WhatsApp - can't run it, without paying money for one of nemory's aweful apps. Facebook - you have to use a particular old version, with the patcher, or use one of nemorys aweful apps. To get the half or so apps I did, with the patcher, I mostly had to look for old versions, that still supported 4.3.
It was planning for gold and mostly getting mud.
I enjoyed bb10 but the apps situation was pretty terrible. I like you, just came from bb10 to win10m.
Mind you, I'm kinda glad I did. I love the HUB, and the keyboards, but the gesture system on win10m is pretty comparable, and the UI is beautiful, even more intuitive in a way. I really only miss the keyboard, the software was definitely a mess.
The OS will always have a place in my heart. The maps app was golden. The hub was a pleasure to use. Swipe gestures simple. They were the first to do flip to mute etc. But tacking on android was never going to work.
For one, google doesn't really want other people capitalizing on their products, open source or not. Hence why they have worked so hard on minimising that stuff, whether its MIUI, amazon, or whatever.
Two, android runtime meant that there was little point in writing for bb itself. You can't build an ecosystem if you provide a competitors alternative app system.
You can't blame BB. They tried everything they could. They even had some okay computer interopability (before some of it broke with the new updates). They didn't have anything to leverage unlike MSFT, for the ecosystem.
And of course, they could never really afford to add much as time went on, as heavily in debt as they were. Security updates is about as much as they could do. But they adapted well, leased out their name to TCL, write software for android, and for enterprise. Down but not out, the keyone seems to have been received pretty well, and its probably a good phone if android is your kinda thing...
I still have my q5 lying around. I thought I would use it for emails occasionally, but without wireless charging, it's not going to happen. If bb10 does ever get a feature update, I might boot it up just to fiddle for a little.