> Many open source office suites exist yet none compete with the ubiquity of gsuite or office

I think this is more about collaboration being hard to solve. Without collaboration gsuite/office offer nothing.

> 3. Both Windows and macOS dominate the home desktop space despite free alternatives existing for a long time.

Mac OS is free too, just free as in beer.

> It seems that enterprises will pay top dollar for service guarantees, integration, and someone they can sue.

In the grand scheme of things, american enterprise is filthy, filthy, filthy rich. I wouldn't imagine they're the best example of rational spenders.