The game has evolved. It's not totally superior technique, grappling especially. Those were days where it was almost an advantage to be on your back because if you were good at armbars you would sub them from the bottom. I disagree a fighter like Big Nog would be able to pull off as many submissions in modern mma as he did in pride. Most guys barely trained defense back then and didn't know body positions that were safe. We still see submissions today but nothing like back then. As far as striking there is much more footwork today that wasn't quite there back in Pride. I love pride I've been here a long time, but Pride was a 2 dimensional version of MMA, where the guys today have gyms that blend in all disciplines.
UFC rules and cage are lot worse enviromment for submissions than Pride ring, so it is not just "evolution and improvement" . With 10 minute rounds with enough time to work, restarts in the middle with no wire barriers to limit movement of your body on the ground, and with GI kimonos allowed, emphasis was much bigger on submission game in Pride. Nowadays in UFC nobody wants bottom position any more, because he wold be easily cutt by cheap elbows and got his head pinned against the fence. Nogueira and Pride guys were foremost fighters of different rules and enviromment, and in that environment their skills and habbist would be successful. In terms of footwork, it is now running around and dancing on distance in big octagon, while in the ring it was a lot more direct.
The problem with the pride HWs was that there we’re a lot of the HWs that we’re really blown up LHWs. Most were also imo just one dimensional fighters like Coleman, crocop,
Size matters less in the ring.
It is a lot easier to reach taller longer guy in the ring where he has less space to move and where he can be closed to corners. Also, with no wire fence, weight matters less becuse you can not use size of your body nowhere that much as in the cage to controll the body of your opponent and enforce.
That's why short guy with brick in his hands like Igor Vovchanchyn, had no problems to reach full sized 190cm HWs like Valentijn, Yvel, Goodridge, Kerr, Baretto in the ring, and they were not able to pinn his body against the wall and enforce size.
One dimensional game + strenght like Lewis, Tuivasa, Rozrnstruik, JDS, Ngannou is just as enough to carry you to the top of modern UFC.