What are the big 3 waiting for to go sub-compact?

[AngryScientist]

sram and shimano in particular. the cassettes keep getting bigger and bigger in the back, indicating the acceptance that lower gears are better for lots of people.

if i want a 46/30 up front and a reasonable gear stack in the back - why do i still need to go to a boutique crank option?

i wonder if any of them are considering a crankset with a small ring smaller than the "standard" compact 34t ring?