This is very true and it is already having an effect. The amount of posts in the development sub reddit has declined so much it is borderline dead. For example the front page of r/javascript is mostly days old posts which means I can visit it once a week and not really miss anything and it has 1,873,376 subscribers! It seems people have recognized that the post quality was garbage and moved on to greener pastures. It truly is the end of an era. I got banned from r/webdev because some said "using PHP is stupid" and I replied "that is ignorant and that the comment itself was stupid" and I got banned for that and I never looked back.
Good riddance reddit.