Could also fuck up and get 51

Using parenthesis can really help if you want to simplify a term or need to rewrite something. I do that all the time because a lot of times you then can just cross stuff out fast on equations or get a common term that just has some factor instead of having a convolutet equation.

I sometimes like to add unnecessary parentheses or brackets to section things off and improve legibility, but I don't do any math stuff collaboratively, so I have no idea whether others would find that disruptive or helpful.

I got really angry because the prettier code formatter insists on removing parentheses, making things less clear. Because it's an "opinionated" formatter you can't tell it not to do that without using ugly hacks.

Sure, logically there are times when you don't need them. But, often it helps to explain what's happening in the code when you can use parentheses to group certain things. It helps in particular when you want to use "&&" and "||" to say "do X only if Y fails".

Some people insist there's no "correct" order for the basic arithmetic operations. And worse, some people insist the correct order is parenthesis first, then left to right.

Both of those sets of people are wrong.

Exactly