Definitely agree on the reduced usefulness for creative play. My kids got a lot of Lego sets as gifts when they were younger. Which is great, I love them playing with Legos. But once they're done with the instructions that's just kinda it. A Star Wars or Frozen or Minecraft themed kit ends up being all weird one-off specialty pieces. They are necessary to make an extremely detailed replica of the Millenium Falcon. But they have no place if you just want to grab a handful of bricks and start building whatever your imagination comes up with. We have a tub full of thousands of pieces and it never gets used. I think it's a bummer that they've pivoted to pushing these intricate $120 kits to adults rather than designs featuring more reusable components. You need to go out of your way to buy tranches of generic bricks if you want to have free play.

The Creator 3-in-1 sets are basically what you're looking for, they just don't get advertised much. A lot of them are more generified and rebuildable, sometimes even more refined versions of more expensive sets or parts of more expensive sets. Maybe the most obvious are the 3-in-1 dragon and dinosaur sets, which to me feel obviously like more generic reworks of D&D and Jurassic Park builds respectively, and have a lot more in the way of generic tiles and bricks than the licensed sets they're derived from.