Sure but they leave it up to the player to to determine if they want the performance impact at the cost of the inproved cpu simulations via settings. They don't shoehorn you into a specific setting because of your hardware.
For PC with its multitude of hardware configs players want and need control and options and choice for settings. That is why higher settings are not locked out even if its not ideal for their hardware.
Crysis lets you chose varying levels of cpu bound physics simulations depending on the physics settings you chose.
Starcraft lets varying levels of non-game impacting cpu bound physics simulations for debris and unit destruction, it also lets you adjust # of sound channels from 16 to 128.
GTA, Bethesda and likely other open world games have draw distance settings that impact not only increase gpu demands but also further the distance various cpu bound simulations and scripts are running.
I've heard post processing and particle simulations for some past games have often relied heavily or completely on the cpu.
Developer Shiny's "Messiah" had a cpu based polygon scaling algorithm (some argue that this is an early example of tessellation) for characters. You could manually adjust character polygon complexity it in the menu based on your cpu, though i'm not sure if the game would auto detect existing cpus at the time and pre-adjust settings like games do nowdays.