There is a big difference between consoles and pc gaming. Depending on the game, the graphics and fps will change. For example, BF3 is still a very graphic demanding game. Consoles play BF3 on a setting that would be low compared to PC graphics from 24-32 fps. For the most part, consoles are low to medium settings compared to PC (highly dependent on the game).
As for FPS consistency, I believe most console games are capped at a FPS of 24-32. PC games frames will change dramatically depending on the resolution of the game played. Some people use the most expensive graphics out there and play games at their max with 100+ frames.
I usually explain systems with houses and furniture. (Game=furniture, house = system) For consoles, you get the furniture to fit the house. For PC, you build a house to fit the furniture. Nothing limits a game from being played on a console as developers code the game to work with the console. However, with PC, devs have no ceiling to design a game thus you have to have the right system to play the game.