Seen plenty of break-ins.. they are 100% crimes of opportunity, full stop.
They grab what it easy and go... they aren't going to waste their time trying to break into anything 'difficult' or locked.
The only reason they'd spend any time is that they've spent time knowing they *have* time and then it isn't a crime of opportunity now is it.
I don't know how old you are, but in the late 90s/early 00s people used to jack CD players from cars all the time, especially ones with cool LCD screens. It was such a big issue that companies used to make disconnecting faceplates you could bring with you so guys don't steal them out of your parked truck.
In those break ins, pry bars, screw drivers, and tin snips were the tools of choice. Doesn't matter what damage was done to the car interior, so long as the CD player was pulled out clean.
My point here is that they offer very little in the way of security. If you don't have it in view, and don't have "sig sauer/glock" stickers plastered all over your truck, you're probably fine. That said, jacking guns from is one of the most common ways that guns are stolen, and it's on the rise.
Your experience may tell you that vehicle break ins are
always opportunistic, but the data says otherwise.
Either way, if your state/locale requires you have locking gun storage and you intend to abide by the law then you have to have something if for no other reason than legal protection.
However, if you're looking to keep your firearms secure in your vehicle while it's left unattended is to do two things. #1 - don't add any gun/hunting/military/etc. stickers to your truck. Some you may be able to get away with, but anything that says glock/sig/etc. is a giant neon sign that there may be firearms in the vehicle. #2 - don't leave firearms in the vehicle overnight. A lot of these thefts can happen in the driveway and the best way to make sure it isn't taken while you're sleeping is making sure it's not there to take.