I am a huge fan of going barefoot and wear my VFFs wherever I can.
However, there are some activities for which VFFs are not a good idea. Downhill skiing might be one. Running a power lawn mower might be another. As a lifelong serious cyclist, I can tell you that bike riding is another.
1. It's inefficient. It's not the really foot that generates power when cycling, it's the leg. There's a reason why cyclist wear stiff soled shoes. It translates more energy, more efficiently to the pedals.
2. It's dangerous. I don't know about you, but I try to keep my toes away from rapidly spinning bike wheels and gears.
3. It will probably hurt your feet, not help them. Putting your bare foot on a tiny bike pedal and then exerting pressure will cause your foot to bend in ways that it's not intended to bend. Don't tell me that cavemen rode their bikes barefoot. They didn't have bikes.
One possible exception might be a short hop on a bike with very large rubber platform pedals, but otherwise go with stiff, thin soled shoes cycling shoes. Clipless pedals are most efficient, but even if you go with old-fashioned toe clips or just plain pedals, you do yourself no favors by riding barefoot or in VFFs.
This, it's a bad idea to use VFFs for cycling.