Might not be any hard data to show it, but it seems to me like the current generation of elites is retiring, and the newer generation of top players aren't quite on the same level, nor are they coming up at the same rate as the old guard are dying.
People don't retire, they lose interest, get busy irl and would rather enjoy the game in its purest and simplest form, 3v3 auto dis ror.
As for new players not dethroning the boomers of the roaring 2010s, the game is extremely complicated for someone to just become a rock star in a day. Nevertheless, 3/4 last seasonal ladders were won by jache, aika and naviiso, who I dont think are from an old generation of elites. Furthermore, the new players in cl 17 div A evidently over-performed. So overall, the arguement new players worst than old players doesn't hold.
Now there's a plethora of reasons why the strat community isn't as active as it once was. From the mtl (being a good environment to train) being down for more than a year, to the modification of the ladders into an activity game, to the accumulation of players that want to improve in old clans which ofc goes to the limitation in clan size, to the detachment of the community, the lack of training and tips between players from different clans, the death or impeding desolation of training clans, the death of the real-time ladder as well as the rt WGL and streaming community and ofc the overall complete lack in promoting strategic games over sead and lotto games. Maybe there's more reasons. But it undoubtedly was more active in the past. The MTL and the AWP include ~50 templates out of which how many were designed in the last 5 years? 5? 6? Probably less.
Is the community now less active than in the past? Yes
Are new players worse by any means, on average or in any way or form? No. It just takes a lot of time and effort to get better at the game.
And that's why I advise you, the reader of my inconsequential text, to visit
https://www.warzone.com/Forum/734956-join-multitemplate-ladder-mtl and join the MTL