InTune/MDMs are finally eating away at the need for GPOs for most use cases. Someone already familiar with AD & Group Policy should be able to easily transition to InTune Configuration Policies. MS even has a tool now to import your GPOs.

There's still a few that don't have direct equivalents, but the list is growing smaller and smaller.

InTune is part of Microsoft's strategy to make everyone dependent on their cloud. It's like switching from Heroin to Fentanyl because you want to get off of your addiction.

Yes and that is a very common case. Windows is designed so that you barely have a chance to deal with your case without Microsoft components all the way. You would need a company with enormous resources to play catch up with the highly integrated and proprietary connections between each component.

It's a rigged monopoly and has nothing to do with a market economy. Once you have been forced to use Windows, you are doomed.