(OOPS, that’s long) TL;DR- Be aware of pitch accent. Beyond that, study it if you want, don’t if you don’t.
I have no intention of this being inflammatory, so if it happens to come across that way to anyone I apologize in advance.
As far as Dogen’s videos, I don’t think I’d go so far as to call him a typical “language bro”. The man got his Master’s degree in Japanese phonetics, and pitch accent is something he’s incredibly passionate about. Some people are passionate about kanji (I’m look at you, guy who can write 𰻞𰻞麺 from memory), some are passionate about 四字熟語, or translation, or 変体仮名 or etymology (語源), etc.
I think he harps on starting early being important purely because it’s easier to build good habits early than fix bad habits later, as well as there being actual biological reasons that make it harder to lose an accent the older you get. I’m not saying people should obsess over losing their accent, just saying it does get harder.
My background is in music and I did take some of Dogen’s phonetics course. I never finished it, nor did I dedicate days and months to shadowing like he suggests at some points, but it’s incredibly informational and honestly very high quality for the low cost of his Patreon. Anecdotally, my Japanese has reached a point that every once in a while people will assume I must have grown up here from a young age. I’m 100% confident that’s influenced by pitch accent in no small way.
Several lessons are (or were) free on his Youtube, so you could get an idea of what he covers without ever spending a cent. My advice to the average learner would be just to watch those, and be aware of pitch as you learn, but only really focus on studying it if you’re truly passionate about it.Grammatically coherent Japanese with an accent is better than perfectly pronounced word salad.
To each their own, as with all things. It’s not worth arguing with people over, just have fun studying what you like 

