And then Valve "underspent" (although perhaps more of an MVP) by taking an existing good-enough chip, perhaps able to get very good yield out of fab (at a time when fabs were costing a fortune), and found yet another corner to cut on a device that is overall pretty low build quality, to hit an aggressive price point. I love my Steam Deck, and I loved the low price, but the build quality is "good enough" at best.
Valve have reversed course with the new generation, having a custom chip now that they've proved out the demand, and I expect the device will improve across the board as they take advantage of higher volumes, and perhaps an ability to price a little higher too.
I wouldn't be surprised if Magic Leap also reverse course (or already have done? are they still around?) by moving to much cheaper off the shelf or pre-existing hardware.