[kortex]

Just because you don't personally encounter it, doesn't mean it's non-essential.

Viton is essential in modern engines. Basically anywhere you are in contact with gasoline, you need fluoroelastomer.

The entire chemicals industry - everything from medicine to energy to commodity chemicals - would collapse overnight if you took away teflon, viton, and PVDF. That's not hyperbole, it's used everywhere and there are no drop in alternatives. Silicone can fit the bill for some purposes, but it has nowhere the compatibility and longevity of viton. We have no real non-fluoronated alternative to teflon.