Mobile Platformer Game - 2D or 3D?

Hey guys. I'm brand new to gamedev / unity. I've watched 8-12 hours of tutorials, my C# programming experience is limited but I know some basics.

I want to make a mobile sidescrolling platformer game. My initial plan was to go with 2D, but I'm considering going 3D. I'm curious how that will affect performance. Is it a bad idea?

Are there any major pros / cons I should consider?

Here's the type of 3D I mean: youtu.be/pwZpJzpE2lQ?t=7325 (timestamped)

 

Personally I think 2D's better but that's just me.