Solarmass Wait, there were other themes like Plata-noir?
I've not run into any black-dark Plata equivalents for Budgie. The darkest seem to be charcoal grey at best.
UB 22.04, for example, has a number of pre-configured themes (Arc, Materia, Vimix, Mojave, Orchis, Pocillo, QogirBudgie, WhiteSur) but none are black-dark in the way the Plata was black-dark. My understanding is that Plata is more or less dead, and doesn't seem likely to revive any time soon.
Solarmass Windows 11 DE is pretty dark nowadays and it looks ok ...
The current Win11 theme does seem to be a bit darker than Pocillo (UB 22.04 default). I like the slight blue cast to Pocillo. I think that both are workable, but neither is black-dark like Plata. I'm not in search of perfection, prefer to stick with default themes, and am satisfied with what works.
POCILLO (UB 22.04 DEFAULT)
WINDOWS 11 (DEFAULT)