Search "YouTube Revanced" on Android. It's a bit of a pain to install, but it lets you customise your YouTube app and add or remove as many features as you want.
These kinds of customisations should be standard for apps people use every day.
You -> Gear icon -> Revanced Settings -> General -> Navigation Buttons -> Hide Shorts.
You need to also hide them from the feed and a few other places. You are not stupid; Revanced has too many options and the settings and large and confusing. It's easier to search "shorts" and toggle everything.
