It would be really cool for people to be able to make money in those markets. It's really lame right now to face competing with free offerings. We're in a post chat client scarcity world.
Nobody is willing to pay for mobile operating systems either. Maybe hardware manufacturers would pay to move Android forward as an open-source project but most likely outcome is a stagnant fragmented mess.
With the choice of Android effectively costing them $5-15 per device sold, manufacturers still chose it.
https://www.howtogeek.com/183766/why-microsoft-makes-5-to-15...
Microsoft would take over. They are in position already, contributing to Chromium.
Why not just bundle it in with the cost of the hardware like Apple does?
Some people would pay for a better browser. For example I pay for Intellij because for what I do is better then the free alternatives and honestly I am afraid if Microsoft would put them out of business with their free stuff we will get stagnation.
Opera is a good example. they did a lot of innovation a Google like tyrant is not needed.
Like, no-one else in the world could possibly have gained access to that ad-space (possibly the most impactful ad-space in the world), and yet no-one even covers this in the anti-trust/competition investigations.
I got really sick of ignoring the constant prompts to install Chrome over the years (and I still use Firefox).
Mind you, at least the EU took them to task for Android service bundling, should be interesting to see what comes of that.