What's the major difference between new technologies and placing pagefile on a separate flash drive? It seems to me that new technologies are just wrappers. Am I wrong?
One can't ever put a pagefile on a flash drive! (What an idea.)
A pagefile can only exist on the system drive and is used for application code "overflow" when memory is full, as well as for the memory dump for a BSOD.
Readyboost is an old technology from the days when memory was costly, small and slow, intended to augment RAM memory with disk space. Do not use.
Superfetch is a technology to preload often-used applications into memory in order to speed their startup times, mostly for slow laptops.
Conclusion: They are not wrappers, but technologies meant to improve the performance of hardware-challenged computers.