Apple / google tax on apps screams for regulation. Taking a percentage cut from something while the internal cost for them remains constant, is monopoly at its best. Minewhile while we're asleep Microsoft is doing their best to promote their own kind of monopoly. Under the guise of security features they are promoting mandatory signing, while what they are really pushing for is to slowly turn the PC into yet another…
For your second paragraph all I could think about was how now is the time for Linux desktop. Then I realised that non-Android Linux could be good on phones too (for the problems in your first paragraph), but for some reason it didn't seem to catch on.
I say this not as a hardcore Linux fan, but as a Windows user of nearly 30 years.