If Bluey is a recent thing, they may need just a couple of more years to appreciate them, but Adventure Time, Gravity Falls, and Hilda are all really good. A year or two beyond that (or not… they’re your kids, LOL), slightly more “realistic” animation like Avatar/Korra and the She-Ra reboot are excellent.

Bluey really is one of the best shows in that specific age range though. Many PBS Kids (maybe distributed by other providers outside the US) shows from the North America are really cute, and even if they don’t quite land for you, there’s usually actual didactic value, but I recall enjoying Odd Squad, Let’s Go Luna, Sesame Street, and Peg+Cat. Then, the whole brony thing happened in large part because My Little Pony Friendship is Magic was so much better than it had any right to be, and its surface level works fine for kids at or just above the Bluey age. The really stylized DC Super Hero Girls series that Lauren Faust show-ran was also good, and better than the (very) slightly more realistic version from a couple of years earlier. Some of the Disney Junior stuff (Rocketeer and Vampirina stick out in my memory) is pretty watchable, but apart from some one-liners and easter eggs, they’re not trying to do too much for parents. Paw Patrol can actually be amusing to deconstruct, but that’s necessary because at face value it’s really bad, LOL. Peppa Pig benefits from some of that same freelance deconstruction, but it is more self-aware and occasionally will drop the mic, like when snotty-ass peppa hangs up on her friend, or Mr. Wolf and Daddy Pig have a very darkly-tinged conversation that references fairy tails.

Things to avoid like the plague: Blippi, Caillou (it’s a bit of a meme by this point, but it really is bad), anything from the “Ryan” franchise.

Strongly agreeing with the other commenter, and adding Owl House and Steven Universe to that list. Great shows for learning compassion and empathy