If you are using clipless pedals you need them. If on toe clips/straps or no toe clips, just use a stiff soled street shoe. I hear that soccer shoes work well. Or for MTB'ing, a lightweight hiking show would work well. I used to wear Vans back in the early '80's. But then I discovered clipless. Went that way and won't ever go back!
__________________
-------
Some sort of pithy irrelevant one-liner should go here.