It's progressed. They were saying boxing had regressed back in the 60s. It's just a myth that lingers about boxing and some fans seem to pick it up and hold onto it, I don't know maybe to make themselves stand out.
You know they're saying the same thing about football right now. There's a big debate on about whether Messi is better than Pele and people side with Pele. It works exactly like boxing, the older they are the more renowned they become. Their myth grows and people willingly choose to believe it. Look at the pattern it runs: Ronaldo is better than Messi, Pele is better than Ronaldo. The larger the myth the larger the support, and boxing feeds on that sort of thing. Saying boxing is dead or devolving is just part of boxing culture which has been around since the year dot.