Hello. I’d say it’s a tricky question as always. Blender could be enough, but it is also great to have many tools in your tool belt. You can learn After Effects, which is is great for motion graphics and post production. And the mix of Blender and After Effects is super powerful for making all sorts of fun animations and doing them 3D or 2D, a mix of both, etc. But if you want to stick with Blender alone, it also works, Blender is ultra powerful and can stand alone as well. After that if you want to jump into other software’s like 3DS Max or Houdini, it’s also great, the more the better. But always keep in mind it’s not the tool, it’s the artist, the person wielding that tool that makes the difference. The tool after a while becomes sort of transparent, much like a carpenter having various hammers, he just wants to build the house.