The only situation where you'd need to type a full path is when you have a name collision. But the suggestion to not worry about collisions with unknown system binaries also said to put the script folder first. In that situation running the script doesn't need a full path, and you won't be running the unknown system binary. So you won't be typing full paths.

Please explain the non-explicit suggestion you see, because I don't see it.

It's clear that "adding your script directory in front of the PATH" means a one time edit to .bashrc or equivalent, right? In normal use you're not typing it.