8GB because it’s the cheapest variant and enough for many players, e.g. people who only play one specific esport title which doesn’t need more and things like that. 16GB is what you get when you use double capacity DRAM chips or clamshell mode (chips on both sides of the PCB). They could’ve doubled up a 4070 to 24GB too but 12GB are usually enough for that class of card while 8GB can botteneck regardless of speed.
8GB because it’s the cheapest variant and enough for many players, e.g. people who only play one specific esport title which doesn’t need more and things like that. 16GB is what you get when you use double capacity DRAM chips or clamshell mode (chips on both sides of the PCB). They could’ve doubled up a 4070 to 24GB too but 12GB are usually enough for that class of card while 8GB can botteneck regardless of speed.