Why would Joe Biden reverse Trump's decision for lowered Insulin meds?

Only because it was something Trump did.. he has no idea why.  What a simple minded idiot he really is!

cus he wanted to

Well, because Trump.   Why would Biden reverse tax cuts for the working people? 

It was part of an overall reversion of Trump's executive orders. According to at least one source, there haven't been many people who benefitted from the order, anyway. I'd stay tuned and see what happens.

He didn't reverse it, he froze Trump pending rules, of which one was an attempt to control the cost of insulin. Not saying he won't reverse it, we'll have to wait and find out.