> existing factories increasing production
All existing factories have maximized their production.
> factories but are not making ram switch
It takes 2-3 years to switch, by which time demand may have satisfied from other manufacturers building additional capacity. So ironically, investing too much into new capacity can be dangerous.
> Large consumers of ram use alternatives, broadening the supply
What alternative exists for NAND flash?
> All existing factories have maximized their production.
Citation needed.
This is almost certainly not true because capacity is not binary but an efficiency curve. As the cost of RAM increases it becomes economical to operate the factory at higher capacities.
> It takes 2-3 years to switch
Citation needed. Who sets the max speed limit for changing?
> What alternative exists for NAND flash?
There is a whole range of suppliers. The alternative is which flash and who manufactures it.