Sorry but you're wrong. Modern games, even massive, system hungry, full boar and roar, AAA budget, open world, high graphical fidelity games in truth... don't use anything close to that much system RAM. In case you don't believe me this is a this a screenshot I just took of resource manager while playing Assassin's Creed Odyssey and I will point that I was playing on Ultra at 1440p and I was in game, not in the menu or anything:
The reason for this as I've tried to explain before is the game engines much prefer to use the VRAM on the card, NOT the system RAM on the motherboard whenever possible. It's faster, easier to access and that is exactly what the developers design their games to do (if they are optimising their games properly that is) because the system RAM is used for system tasks such as the OS and desktop apps like Chrome in my case. Results will vary and it depends largely on how much VRAM is on your particular graphics card.
I still maintain that 16Gb is better to play it safe, which is what I have and you might have noticed I'm using more than half with both AC and Chrome running. But for lower tier setups I still think 8Gb will play most modern games fine.