While my Operating System is installed on a SSD, i install games like Factorio on my HDD. When running on a hard disk, Factorio takes a long time to startup and show the main menu. A significant percentage of that time is spent on IO, reading the game assets from the slow hard disk.
This isn’t storing the game in RAM; it’s caching it — which isn’t an effective strategy if you actually want fast load times and do any sort of substantial disk IO between system boot and game launch.
Not tryna get too analytical on a meme post, but tmpfs is the correct way to do this for anyone wanting to pull this sorta thing off seriously.