This is, I think, because it's easier to learn than ever, ham radio equipment is more capable for a cheaper (adjusted) price, and ham radio has grown tremendously worldwide due to all barriers being lowered a bit.
CW is very popular, especially given all the other options that are easier.
That it's a smaller percentage of hams that know CW than before is another way of saying ham radio has expanded well beyond CW and the population has grown. But if you have a finite resource (bandwidth) and it's in significantly more demand than ever before, it's a hard argument to suggest that it's not 'very' active.
i have attended club meetings and activities, hamfests local and around the US, participated in online forums etc for many years. morse code isn't a big topic anywhere outside of very specialized contexts, such as field day and qrp operation.