The classic brick buckets are still widely available, right next to all the themed sets and the replica sets (which are explicitly marketed to adults). Not sure what the complaint is here, that the general public don't share your taste?
The themed playsets aimed at 5+ children are leaning towards detailed modeling with many tiny 1x1 pieces.
The one-off nostalgia-driven sets like the Lion King's Castle, the remake of Eldorado Fortress and the Galaxy Explorer are intentionally released as one-off sets with a time distance in the release date, and not as a part of a regular play theme.
But yeah, even like 90% of the ones that appear to be marketed to kids suck for kids to play with, now. They look nice on the box, and on a shelf, though, and I guess that’s what shifts units.
For example, they really like those tiny little inside thingies.
One of the more interesting experimentations was Lego Architecture Studio.
All white (well, some translucent for glass/windows), 1200+ pieces, no instructions, but a book discussing some general architecture and building principles particularly with respect to Lego:
https://www.amazon.com/LEGO-Architecture-Studio-Building-Blo...
One of my favorite sets, though architecture in general is a particularly interest/hobby of mine.
That's exactly what was in buckets of Legos that I got as a kid in the 90s, so I don't think much has changed. It was almost entirely 4x2s and 2x2s of different colors back then, too.
I get why but it feels less timeless than it used to, perhaps with less emphasis on creativity-led play. But what do I know - I'm a grownup.
And their directions were always a ton better, for sets—though they used to be more like spot-the-difference puzzles than they are now, which I credit with my burying the needle on a spatial reasoning test in high school, so I’m kinda sad they lost that perhaps-accidental pedagogical value in the shift to the you-can-follow-them-in-your-sleep, modern style of directions.
But maybe the knockoff competitors aren’t as obviously-shit as they were in the earlier days?
I wanted to like the cheaper brands but none of them have the same Lego engineering quality. We dusted off some of my old lego and the bricks still fit perfectly with the new bricks 30+ years later!
"They're miners... in space! They mine green Energy Crystals!" That's all you need. There was a K'nex mining set about the same time. Good stuff.
Then I realized that most of the catalog was like, Lego Harry Potter. Yeah, I really am complaining about what everyone else buys. I was up to my nose in Harry Potter merch already, I owned all 7 books. I wanted more Rock Raiders and Insectoids.
Heck, my kindergarten daughter likes that formula. I'm pretty sure there is a marketable business somewhere in there, but maybe not at sufficient scale