I used to feel the same, I feel like the real turning point is once you start ranking your own websites a lot (self proof of concept) and when you reach the point
where 90% of what people tell you is stuff you already know.
When I realised that I can no longer learn new things watching many seo content then I realize their isnt much more many of these people can teach me.
Then you need to dig deeper, you know most white hat, now you start learning grey hat, things you try to tell yourself are not THAT bad morally but can make you money.
Then you reach to black hat, which is infinitely bigger but filled with infinetly more misinformation, untested concepts and google telling you "you are not that guy"
when stuff you test that worked for others does nothing for you.
I dont think their is ever an end to black hat information, all you will really ever want is just one winning method to make your money then you start not caring about most other
niche black hat things until your method dries up and you need another.
I think most people can be allowed to call themself an SEO after they know 99% of white hat material and a few grey and black hat stuff.
You can obviously make a lot of money doing white hat SEO work and outreach for companies etc.
If money making is the proof of your SEO to an extent then you dont actually need to be some mega nerd to be doing well.
You will have black hat "experts" still making little money when their methods dry up over someone who builds a legitimate business.
then you have black hats who earn your yearly in a single month.
just my personal take.