remember if you do get a HDR TV/monitor that just because it says HDR on the box doesn't mean it's gonna be good. HDR isn't created equally as there are different standards. you have HDR10, HDR10+, Dolby Vision, HLG.
HDR is measured in different ways and therefore has different levels. It's measured in brightness, colour gamut, dimming technology, black level, and latency. so you could have a display that only does 400nits with sRGB across the entire screen and therefore illuminates blacks. it would still technically be considered HDR so that'll be slapped on the box. Of course, that kind of display wouldn't be able to match the quality of display that can do 4000 nits, Rec. 2020, and has control at pixel level meaning they can be turned off completely for infinite contrast ratio.
my PC monitor was advertised as being HDR but it fucking sucks. well honestly it wouldn't be so bad if it could dim blacks. it's basically the same as the first example i gave above. 400 nits, srgb, and full screen illumination. my TV can do up to about 800 nits, rec 2020, and since it's OLED has infinite contrast. the difference is night and day. i never turn on HDR with my monitor but will always watch movies in HDR when i can on my TV.