Is integrated/non-upgradeable RAM the unavoidable future for all consumer-grade devices? Is there any sort of standard on the horizon that would enable the massive memory bandwidth to compete against the M1-style approach?
It's just not catching on, because of course it isn't. Manufacturers have no incentive to let you upgrade parts on your own.
There just isn't a free lunch here, it's an inherent design tradeoff for these kinds of chips. The CPU is just along for the ride, in this case.
My completely-bullshit opinion is something like "I think it's attractive for a lot of mid-range or lower end SKUs, so you'll see it more frequently." It's attractive because you save a lot of power and components with this kind of design. It would be interesting to see this kind of design (APU) in a socket-able factor too, but who knows. It's also attractive for a certain class of high-end design too (like Grace Hopper), but I think you're going to see RAM sticks for a while yet in the mid-to-very-high-range.
This is completely bullshit because it is based more on vibes and basic technical design points than any kind of market forecasting or anything like that.