I agree with all of the above. If you can only have one, though, I think MSFS2020 is the future even with its various bugs. Once you've flown the graphics it's hard to go back - even when the autopilot does weird stuff. Sort of reminds me of the old song about U.S. soldiers returning home from France after WWI. "How ya gonna keep 'em down on the farm after they've seen Paree?"
The main current downside in MSFS2020 in my view is the lack of legacy jet airliners like the early Boeing and Douglas 707s, 727s DC8s, and 9s, etc., and no apparent interest by current devs in bringing them in. There are multiple and redundant versions of the same glass Airbus, Boeing, Embraer, CRJs, etc. Captain Sim - where are you??
If you've got the computing horsepower, disk space, and internet speed and can afford multiple sims I'd go with MSFS2020 and the current version of P3D. That way you've got pretty complete coverage of the modern glass and the FSX/P3D carryover of many different legacy steam gauge aircraft.