Emulation, some switch games require 12GB of ram, advanced computational photography(HDR+, super night mode, etc), running those AI models locally on your device (think chatgpt, or something other model for audio, pictures, etc) 6 and 8GB are no longer enough. I run into multi tasking and app reload issues with 6GB of ram, if i disable samsung’s ram plus. But, for the average user 8 and 12 should be sufficient.
As for your question regarding power consumption, it could be more. But, it could also be negated by reduced app reloads. I wouldn’t worry about power consumption. Your display, network modem, and the SoC are one of the biggest sources of battery drain. Ram hardly adds much to the equation.