Literally took most of the words I was typing and put them in for me, I don't understand how he banged on about things like 120Hz and then recommended a MateView which is lower PPI and 60Hz lol. The usual YouTube/Tech-Review tripe that wants all of the latest and greatest features with zero grounding in reality. Is there even a 5K Monitor with 120Hz on the market yet? I do agree it's expensive, but Apple tax always is.
The YouTube reviewers don't understand the monitor/tech market at all. They only get the Apple ecosystem (ProMotion on iPhone/MBP is good, I want it in my 27" display too!). A lot of the PC/tech reviewers don't get the Apple ecosystem either (they say make it 4K but 120Hz, which is fine but Apple users would never go for a drop in pixel density). If this was a 4K120Hz it would have been the biggest flop of all time - literally no longer a retina display.
There's no single 5K 120Hz at all, in fact there's no panel that can do it.
If you want 27" or larger, and >200ppi, there are only 8 panels in the whole world right now. 5K 120Hz would be more than Thunderbolt 4 or HDMI 2.1's bandwidth as well, we'll need DisplayPort 2.0 for that (and no, DSC isn't an alternative for a colour accurate display).
All are 60Hz, and all the 27" ones are actually revisions of the same panel in the 27" iMac and LG Ultrafine. The 32" 8K panel is used in Dell UP3218K (which is £3500). The only panel missing here is the Pro Display XDR (32" 6K) but that's an exclusive Apple panel so wouldn't show up in these databases (and exclusive panels are super expensive).
Ignoring 5K, there are some Mini-LED / local dimming monitors with 120Hz:
At 27" 4K (164ppi), there are ASUS PG27UQX and Acer X27S, both are gaming-oriented (rather than design). Both are in the £1500-2000 region and cost more than the Studio Display.
At 32" 4K (138ppi), there are ASUS PG32UQX and Acer X32, again both are in the £3000+ price range.
If you want colour accuracy, e.g. ASUS ProArt line which is more comparable to Apple displays, you lose the 120Hz and then you're looking at £2500 for a 27" 4K with local dimming (ASUS ProArt PA27UCX-K).
Not sure how people were expecting Apple, of all people, to take the £2500 ProArt, up the resolution to 5K, add 120Hz to it, and then sell it for £1500? Was never ever going to happen.
£1500 for a 27" monitor either gives you 120Hz/local dimming, or 5K resolution. Take your pick. You can't have both.