Yes, Companion AI is curious. But, it used to be a lot worse! Over the course of development, the Developer made a few tweaks to address some of the worst behaviors (standing on a damage tile, for example). Yet, as any player can testify, Companions do the darndest things.
Some things you can do to make Companion AI a little more predictable.
Give your Companion Passive Skills only. That will help mitigate silly use of Active Skills.
Set your Companion to attack only near enemies. It's not a prefect system, but that limited range helps avoid them running off into the far distance, or just standing by.
I've long advocated for a quick button to toggle basic Companion commands.
A long time ago, it was possible to push Companions into traps to set them off. It was the quickest, and easiest way to clear out traps. It was also a great way to get revenge on an idiotic Companion.