My personal opinion about 2.1? A lot of the tech is very cool and will be great, eventually. But it's also very new and a long way from being fully mature.
VRR is pretty nice, as is eARC (which is available for some TV's even if they aren't fully 2.1), and it'll definitely be great for things like 8K. But all of these things have caveats, including needing a receiver to also be compatible to run things through it, early implementation bugs (VRR had issues with certain games at first; not sure if that's still the case, etc.), and unforseen compatibility issues with future implementations.
Personally, as someone who was an early adopter of 4K and had quite a few problems with my first 4K TV (HDCP handshake issues, audio sync issues, certain framerates in certain resolutions not being supported that only became an issue once more content became available, etc.), this time I got a nice, mature 2.0 4K set, and I'm greatly enjoying it without many issues at all. While I did enjoy that first TV, this experience is much smoother. The next time I upgrade will likely be when 2.1 and 8K are somewhat matured, VRR is in wide use, etc. as I'll need to upgrade receiver and TV, but that's a ways off. (Hopefully some new techs like Micro-LED offering the best of both LCD and OLED combined will be available too).
Just my two cents. If you don't mind being an early adopter guinea pig, there's nothing wrong with that, but I would advise against expecting to get an early 2.1 set now and expecting it to do everything well down the road when 2.1 features really take off and are widely available. So I'd probably get something mature now, possibly with a few 2.1 features you want (eARC for example), and enjoy it. OR, if you really do want to wait, I'd put off upgrading for a year or so until things get a bit more mature/finalized/in wider use, then reevaluate then.