I'm thinking along these lines too, although sony doesn't currently support HDR10+ so I'm a little torn on this and there's also the issue of HDMI connections/frame rate as reported below:
PlayStation 5 Just Gave Most TV Brands - Including Sony - A Serious Headache
HDR10+ seems to going nowhere though it remains to be seen if Sony will even support Dolby Vision on the PS5.
If connected to a 60Hz output display (which is everything more or less) your only going to get a 60fps at best.
With 120hz output displays and VRR the problem is a lack of standardization, really Sony should just come out and mandate a specified VRR range of 40-120fps that all games must support on the PS5, as pushing a perfect 120fps is unrealistic given PS5 hardware and developer constraints.
Thats why VRR in tandem with 120hz output makes the difference smoothing out variable refresh rates.
Support HDMI-VRR 40-120hz TV's and Freesync 40-120hz PC monitors regardless of resolution, it can be 1080p, 1440, 2160p/4K and the console just internally scales up or down depending upon the output. All PS5 games would benefit and just run smoother, feel better.
What will undermine the above is if different TV makers start implementing different ranges beyond 40-120hz and only select PS5 games benefit leading to confusion.
This is what Xbox did when it added support for VRR/Freesync, it never specified a range and there are 60fps games that are still capped at 60fps even if running on a 120hz output display and 60fps games that don't work at all with VRR/Freesync.
Freesync PC displays are cheap and are the easy way to drive adoption, TV's will take a lot longer to spread through the market, of course if Sony dont support Freesync either then that will be another blow.