>>113094995He's talking about story continuity, issues leading into each other, long-form storytelling, etc, something that was a big deal in the 80's and 90's. Writers passed a baton to each other.
Now we very much have the "put the toys back in the toy box" mentality of leaving books back where they started when you're done with your run.
I don't think this stuff is the CAUSE of the decline in quality, and I don't think it's inherently a bad thing, it's just why the current style isn't really as interesting to me anymore. All my favorite comics are ones that build heavily on what came before and ran for years, developing over a long time. When those versions of the characters quit existing, I quit caring about them.