Yeah, I'd like to be able to investigate more as well.
Investigation could be used to determine what kind of lock or trap you're dealing with. Is it a cheap lock? And ancient gnomish-made lock? Rusted half shut? You don't get any information at all, which makes it hard to know if it's reasonable to try and open that container. Mechanically speaking, you roll an Investigation check. If successful, that gives you the DC for the attempt. If you fail, you don't get the information and will just have to guess.
