The bigger question is where does silicon go after 7nm ? The next step smaller is prohibitively expensive and difficult, perhaps now the only realistic way forward is going to be in different layouts / technologies?
I guess we'll start to see Chiplet mesh architecture come to GPUs.
the next couple generations should be sorted at 7nm
first gen = small 7nm dies
2nd gen = big 7nm dies
3rd gen = new/improved architecture on big 7nm dies
After that it's either move to 5nm or design something different like a chiplet architecture