Some clarity on 120hz.
1080p@120hz is doable today. Even on the Xbox One. It's a HDMI 2.0 standard there.
Future proofing is the 4K@120hz modes. That requires HDMI 2.1 and more expensive cables that can pass the higher bandwidth. Neither PS5 or series X is powerful enough to do 4K@120fps gaming. The target is 4K@60fps which most TV's today can do. VRR is really the only reason you want to future proof for HDMI 2.1 if you even notice screen tearing or poor frame rates.
Samsung totally fucked the xU line after the NU8000 (I have that one in 82"). They stripped it down when it went RU and continues to be the bottom of the barrel in the Samsung line. Most notably, it got rid of local dimming completely. Not that local dimming was spectacular on the MU8000 and NU8000 before they neutered it even more.