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.
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.