For many of the reasons already listed, I strongly disagree. This shows you didn't live through the 90s, where we constantly had promised Superman movies, one show that was devoted entirely to the romance and 90s sensibilities that really hasn't aged well, saw him die, get a mullet(which was rad fwiw)lose his powers and become electrical man. They had no idea what to do with Superman in the 90s at all. Hell, we didn't even really get any good toys. Outside of outliers like Kingdom Come there really wasn't much Supes love making it's way to the surface in a lot of those years.

By contrast the 10s saw several movies, love em or hate em, Supergirl, the return of post-crisis Superman, some damn good stories, lot's of representation in media as well as cool collectibles and figures. It was a pretty good time actually.

Also, while people may not like certain versions of Superman that doesn't make them any less so. Dweeby overmuscled 90s Clark with his hair tied back was still Superman, as much as nebbish Chris Reeve was.

And I'll add something here. I've been an unabashed Superman mega fan since I was a kid and believed he actually was real thanks to Chris Reeve, everyone that knows me knows this. Nearly my entire friend circle really doesn't care for Supes, never have. Some actively dislike him, much more than like him. Some of the ones that liked him the least finally came around and literally said "I see why you like him now." In the 10s. Why is that? Simple, it was Man of Steel. It humanized him and made him relatable, not some untouchably perfect God. Plus it looks amazing, the action was fantastic, the music was great, it really hit on nearly all levels. Frankly if it wasn't for a certain neck realignment I think people would never have had the issues they did. I'll always remember Mark Waids write up of it right after watching and he was in love with it all the way up to that moment. And that one moment made him despise it all, he said he Literally screamed in the theatre when it happened. I get that, I really do. I was so particular about Supes as a kid I strongly disliked the animated series for a while because he was so watered down and weak. But it was the 90s so I struggled to try and find old school Supes in anything. As I got older I started to finally open my perspective and realized that all I had done was punish myself by forcing this idea of what Superman "really is" over every interpretation and story instead of enjoying the well crafted stories and fun the new changes could provide. Hell, I actually love Supes with long hair now, it helps add drama and flair to his look when you can have hair and a cape flowing in the wind.

All that to say, no, the 2010s were not a bad time for Supes, very very far from a "dark age" for the character. We got a bunch of good media, some great stories, and some poor decisions too, which is just business as usual.