Honestly, they sort of do. I would definitely call any 60% with custom QMK firmware with function keys and layers a non-standard layout. For the alpha keys, the benefits to switching from QWERTY to say DVORAK or something are largely still theoretical. No one to my knowledge has proven definitively that it's actually superior. And it's a common myth that QWERTY was designed to slow typists down. It was designed to place the frequently used keys further apart from each other, which is not the same thing as trying to slow down typists. If that were the objective, you'd find yourself doing awkward pinkie reaches for 'T' and 'E' and the like.

But even if DVORAK was superior, mastering it comes at significant costs. Chiefly, switching to a custom layout with function keys and stuff doesn't reprogram most basic typing, so you can jump on someone else's conventional keyboard pretty easily. If you reprogram yourself to be a DVORAK master, you are looking at some serious potential hindrance in flexibility since we live in a qwerty world.

There's a lot of people in this hobby that use Dvorak, and the other obscure layout that I don't even remember the name of. Some even design and sell PCBs/entire kits for them. Most of the keyboards seem to use QMK, an open source, programmable firmware so you can do whatever you want.

There's a lot of debate on those layouts and their usefulness. There's people that swear it saved them from RSI and there's people that say nothing can be proven about the health benefits of any alternative layout. There are a lot of people that switched to an alternative for a few weeks, months, or even a year and then went back to qwerty. I've stuck with qwerty so I don't have a lot of knowledge on the subject.

COLEMAK? is that the "other obscure layout"?

That's one of them. Not sure how obscure it actually is. I'm not very knowledgable about alternative layouts, I just see the names come up frequently.