@Ben_KC TBH, I can't even blame them. You probably won't encounter itertools in the wild too often. I used to use itertools a lot very long time ago but nowadays I maybe import `chain` sometimes, maybe `product` once a year, and that's it. Most often, writing a generator function with some loops gets things done without much boilerplate.
UPD: not to say it's useless, just not common.
@Ben_KC Stop reading YouTube comments 😂
I mean, I'm kind of kidding, but also kind of not, because there's no quality control on YouTube comments and a lot of them come from people with no relevant expertise, so you'll find a mix of useful insights and utter nonsense. And there are enough people out there who either believe the nonsense or act as though they believe it that it's hard to tell the difference.