It's possible to be a good Peach player having barely any tech skill at all. But to start working tricks into your game like instant FC attacks, wallbombing, chaingrabbing, techchasing/combos, shield pressure, turnip approaches, edgeguarding, and so on, you need to be really precise and have your timings down well. Some don't call this tech skill because you are usually not pressing buttons at blistering speed (except for IFC/SP), but it's a skill that definitely takes work and will elevate you from good to great.