Yes. Mistakes are necessary sometimes.

For sure

You can learn valuable things at any time, there is always something to be learned, if you are looking for the lessons

This site

Yes, definitely. Even wisdom itself can come from making unwise choices.

Learning via mistakes is a lesson you don't forget.

Yes. A lot. You can learn from unwise decisions and opinions that people are not always reasonable, not sensible and insist on stupidity as if their life would depend on it. Take that into account when you want to do something good. You should not be surprised facing opposition when doing something reasonable. People love their fucked up beliefs much more than truth and reason.