Never got around to The Backrooms, but the follow on Oldest View / Rolling Giant series of videos are absolutely fantastic. It captures the tension between curiosity and dread perfectly, which seems to me what all of this fascination with liminal space is all about.

On a technical level, his work is brilliant. With no budget, he puts me in a CGI space that I really can't tell is CGI, and invokes all of the feelings that are familiar to anyone who has snuck around where they really shouldn't be.

https://en.wikipedia.org/wiki/The_Oldest_View

I can only second this. I personally got more out of “The Oldest View” than I did out of maybe half of all commercial shows I recently watched, and I consider myself pretty picky.

At a meta level, there’s something amazing about fiction that feels like it ought to be constrained in what it can do by its budget/production capabilities and then constantly surprises you in execution.