I totally feel that.
I also belong to a few discords where the community skews younger than EN world, and there are a ton of questions along the lines of how do I start being a GM? Or how do I do some very foundational thing for GMing?
I think the Internet videos are not 100% a good thing but more a mixed bag. I think there are best practices, a sort of cultural transmission, that used to happen when we were learning from our friend Mike’s older brother or whomever.
I believe that transmission gets lost in translation, listening to YouTube videos or watching live plays. It’s not that the advice is terrible - well ok rarely it’s IS terrible - rather it’s that the advice doesn’t take into account the needs of that GM, and it’s not being given in a conditional “if you’ve got this sort of group / if you’re this sort of person, here’s what you can try” way. And that can feed misconceptions.
Often with new GMs I’ve mentored their game prep priorities are skewed (eg. thinking they need to do all this worldbuilding before running the game) or they think of things that are obviously a bad idea to those of us who have experience… but they don’t know any better. They don’t know the questions to ask to interrogate their own design ideas involving taking the party captive. They don’t realize that relying on a chase scene as the exciting opening scene might not work when the druid has the entangle spell. They don’t know what will really help them feel prepared (eg one GM needing a list of names but another rattling off fantasy names with ease).
Many new GMs don’t know how to conduct a productive session zero - they wonder what to ask, how to facilitate conversation about what everyone wants, what even the list of “here’s what we might choose from to describe what we want in D&D” looks like!