The benefit of having unused RAM is that every program you are using can remain in memory for quick multitasking access and when you go to launch a new program it can be loaded into that unused RAM without unloading any of the currently running programs. What part about that is a misunderstanding? Would the user be better off if the application in focus aggressively reserved RAM it didn’t need to slow down every other running application? Because that’s what Photoshop does
The benefit of having unused RAM is that every program you are using can remain in memory for quick multitasking access and when you go to launch a new program it can be loaded into that unused RAM without unloading any of the currently running programs. What part about that is a misunderstanding? Would the user be better off if the application in focus aggressively reserved RAM it didn’t need to slow down every other running application? Because that’s what Photoshop does
The part where you assumed 20GB is 100% of OP’s RAM, leaving nothing for any other programs.