I don't agree with you, almost in every industry companies go for brandables and pay big amounts for them including in XR.
Examples:
JauntXR.com
XRnation.com
InceptionXR.com
Pixvana.com
ConductXR.com
8i.com
ProsperXR.com
EmpaticaXR.com
The list goes on.
The reason for this is because companies may start in a specific area but they may want to expand into other areas in the future and if they start by branding them self as an exact match keyword there is a big probability they will have to rebrand in the future.
I think this companies are well aware of this because many already had brands established with VR, AR, MR etc... as they grow and need to expand into other realities now they have to rebrand their establish brand, doesn't make sense your company be called something VR when you now provide AR, MR, AI as well.
As the term XR gets more established i think we will see more companies branding with a brandable keyword + XR and vice verse, i think many will probably brand them self with terms that won't even have XR in the name such as Pixvana.com, 8i.com etc... but most will have the term XR in my opinion because it will be a term so recognizable they will have to use it, i mean it's just like VR and AR it explains instantly to the consumer what they are all about.
Example: If your a consumer and your searching for extended reality in search engines when you see Pixvana.com and JauntXR.com which one will the you the consumer instantly think "this is a company that specialize in extended reality", of course its the one that has XR in it.
Pixvana will have to invest a lot of money to educate the consumer that their a big company that specializes in extended reality where Jaunt XR will have to spend much less because the name or domain already does much of the work for them.
This is a great example of the benefits that a powerful domain name with good potential will have, it will be short, easy to pronounce, remember and will identify to the consumer what their company is all about, in return and long term it will save the company millions in marketing and branding.
Of course exact match keyword domains will also have high value there are companies that have no interest in expanding to other areas, they only wan't to be the "best" in their specific area and what is better then a domain name that identifies the exact industry, like for example EducationXR.com, XRGames.com, CasinoXR.com, XRDesign.com etc...
Also you mention "There are still many more XR brandables names still available, but no one is regging them, because counting on those to sell is like betting on the lottery rather than educated investing."
Well your right when you say brandables are more of a shot in the dark then exact match that's pure logic but doesn't mean there isn't opportunity in them and even brandables have a pattern otherwise places like brandbucket wouldn't be so successful.
In the short XR domain sales reported mine and
@Elad n were brandables does this mean out of every XR brandable reg we were the lucky ones that won the lottery? if that's the case then i and pretty sure other members here that have brandables and been receiving low to reasonable offers on them have won the lottery many times.
Also i been reg brandable XR domains, seen members here that also been doing the same thing and domains that were on my list to reg are no longer available so i think when you mention "There are still many more XR brandables names still available, but no one is regging them" it's not entirely true.
I do think exact match XR domains will sell for a lot and have a lower risk especially ones in the advertising, marketing, media and design space those probably are already receiving very reasonable offers for sure since this spaces are currently "hot" and trending in XR right now but as XR matures to other areas the offers will start to increase IMO.