Let's say you have a very bright light source, and that light source results in shining a full 100 Watts of light into the sensor of your camera (I'm using this not as a typical example but because it will make it easy to scale the answer). Photons of visible light have an energy of at minimum 1.5 electron-Volts (800nm red light), which means that 100 Watts of light represents 4.2e20 photons per second.

And that means that with only 100 Watts of light reaching your sensor you cannot attain an fps higher than 4.2e20, because at that speed you'd only get on average around one photon per frame. More realistically you need tens of thousands to millions of photons per frame to have some meaningful level of dynamic range and spatial resolution, which limits the fps to around a quadrillion fps per 100 Watts of light falling on the sensor.

Though once you get into that range you also have problems of signalling, we don't really have electronics that work at those speeds.

the signal is extremely weak, the conventional 'shortest-pulse' is around 5 femtoseconds.