I’m speaking mainly about the mainstream side of things. There’s still tons of great music coming out, but the quality of mainstream music back then was quite higher than today, and back then, songs like that were often considered generic garbage (which I always disagreed with).
All you say comes off as ultra vague, no examples, everyone has a different view of what's what.
Mainstream, like that bubblegum crap nerd shit? Spears, Taylor Swift ,Spice girls etc? Music is produced targeting pre-teens and that targeting to those that are into all those super hero type geek films and those fake reality type garbage shows, and yet they still can have a catchy tune once in a while, like a commercial jingle. That grunge era was so overrated it's funny, not many good songs from that period, a lot of crap that sold though.
I visited some friends a while back in Quebec, many are lifelong musicians and one friend has a recording studio and they all still have their fingers on the pulse and they were saying that there is not much going on that is catching their attention, not much to get excited about anyways, be it English or French. Keep in mind no one is under 60 and were raised with classic rock, rock, hard rock, metal, punk, prog pretty much but diverse at the same time, a good catchy tune is a good catchy tune even if it's not good.
So I had the opportunity to introduce them to music and artists they had no clue about, showing videos and live performances ( I made a mention of this some time ago in some posts, showing some artists, just the tip of the iceberg ) and now a bunch of them are coming over to see some festivals and artists at solo shows. I'll introduce them to a friend and his band that's on the bill at one of the festivals, though not our fav type but they are fun, cool, chill guys.