Wouldn't hardware determine render time not quality?

I can't speak directly to animation, but in general, start doing the work you want to, and then when you hit a problem, then look at upgrading.

Old computers generally can pull off the same quality, just slower.

I think you're starting at the wrong end of things:

If you want to do animation, learn how to draw first. Once you've learned how to draw, learn about visual composition Once you've learned about visual composition, learn about filmmaking Once you've learned filmmaking, learn about animation Once you've learned about animation, learn about 3D rendering as a tool to draw what you want.

But it all starts with learning how to draw, and you don't need a super powerful PC and GPU to do that.

You don't even need a PC: Get a stack of paper, or a sketchbook, and a pencil.

If you find yourself the type of person who likes to draw the same thing over and over again, maybe hundreds of times to get one scene, you might be an animator!