For things currently running, Steven Universe and Voltron Legendary Defender are better, and Miraculous Ladybug is close.
For past shows, Avatar: The Last Airbender and The Legend of Korra.
These are all very different shows so comparing is hard (and I didn't even include anime) but these shows are better in my eyes than My Little Pony (not by too much though).
This does remind me of an interesting thing I thought of though, and that's that there are essentially two kinds of cartoons: Kids to preteens cartoons and adult cartoons. There are very few aimed at the audience of teens. The few I could think of are Steven Universe, Gravity Falls, Avatar: The Last Airbender, The Legend of Korra, and Voltron Legendary Defender. Lots of people would consider these as kid shows, but they are definitely directed more towards teens than kids. There aren't that many of them though, with the overwhelming amount directed at kids and majority of the rest at adults.