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.

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.