They literally couldn’t pay the devs. Netflix for instance flat out refused to have blackberry pay for 2 full time devs to maintain an app.

Netflix looked at the market share and determined that there was 0 benefit. The people that were on blackberry devices already had a Netflix account.

Additionally Blackberry store apps were compelling for devs. Dev feedback included ease of development and more importantly they made a lot more money on the blackberry store than on iOS/android, both because the cut was better and they could jack the prices up because the customers were not nearly as frugal.

To get into mobile would require a massive overhaul of windows apps to get them mobile-friendly

Oh look, that’s exactly what they did and now we have PWAs for lots of apps. Maybe MS is getting ready to take a stab at mobile again.