There is so much wonderful indy wrestling in the world. You'd previously mentioned that New Japan bores you, so that would explain why you don't know the names of Tetsuya Naito, Michael Elgin, Will Ospreay, and so on. It also tells me that you don't watch much Ring of Honor, since there is still a good amount of talent overlap between ROH and New Japan. If you happen to be on the west coast, New Japan is having their first US shows (technically, though they did 3 shows in the northeast in 2011) in Long Beach in July. G1 Climax series, which is huge news (but kind of a pain to explain the idea).
WWE produces enough content that it's super easy to get your fill of wrestling every week just by watching them.
If you want to see great wrestlers before they go to WWE, then you have to keep your ear to the ground on the indies. Tyler Bate and Trent Seven are huge in the UK (and, ahem, also still our Tag Team Champions). The current crop of NXT talent are almost uniformly guys who were huge on the indies - except for maybe Liv Morgan, who went straight to WWE.
Not hearing of them tells me that you're not paying attention. Please understand I don't mean that critically - like "you're lazy and not paying attention" is not at all what I'm saying. I get that following the indies is a big ask if you follow all of WWE's content, and have time for work, family, other non-wrestling hobbies. It's a lot - easily overwhelming. But not hearing of these people isn't their fault, necessarily. They're working a lot at a level that you're just not following. If you want to see who's going to be huge in the WWE in five years, follow the indies now. That's what I'd recommend. Maybe follow New Japan, too. 14 month ago, Nakamura, AJ Styles, and Gallows/Anderson were putting on incredible matches there. They left, and NJPW still had a stellar, stellar year. The people who said Nakamura was a god among mortals as a wrestler in previous years are now recognizing the talent of Naito. Holy crap he is so good.