External Graphics Card with MacBook Pro

13-in MacBook Pro is a portable-optimized computer that can run on batteries, and comes with Intel integrated graphics, only.

Apple does not even consider that good enough to run its 15-in built-in displays for even slightly-graphics-challenging purposes.

So yes, in my opinion, you should buy a more-graphics-capable computer. Starting with a computer with a graphics deficit and adding a box on the outside is not a sensible approach, in my opinion. You get an excessively expensive setup optimized for nothing in particular.

Do you even need portability? With a MacBook Pro, you pay dearly for that portability.

First and foremost, why are you considering this complex expensive alternative to a Mac that was sold as a portable computer?

What problem, EXACTLY are you trying to solve?