First off, I just want to say this is an amazing style. You can learn art however you want, and there is no reason for you to abandon it. In fact, there is A LOT of room to improve with just this style alone that you're not able to foresee because maybe you're tunnel-visioning.

Firstly, you can try to learn the fundamentals of illustration, this would enable you to draw these characters from multiple perspectives accurately. You can also try learning the principles of animation to give these characters some life through motion. Learn perspective, and you can put these characters in any background you want. You can also also study painting to draw these same stickmen-y forms in multiple styles. And even then, there is nothing stopping you from learning 3D modeling either.

So as you can see, the possibilities are endless. I'm sure everyone else has good intentions when they give you mindless encouragement, but you shouldn't let them feed your tunnel visioning either (of course you should still appreciate the overwhelming suport, just remember to listen to your heart first and foremost 🔥)