Yeah people really overestimate the security of regular keys. The key of my 1985 Mazda would open about 10% of all 1985 Mazda cars. The lock of a standard US house door can be picked by a 9-year-old child in seconds (source: my 9-year-old child). They are superficial security measures.
US doors always allow unlocking from the inside (fire regulations?)...
I'm talking about from the outside. Anyone can learn to pick a mainstream US residential door lock, even Hollywood film style, with a paperclip, in seconds.
With or without a tension wrench?
Here's a (crop from a) photo of a small child who has just picked a front door lock with a bent paper clip and a small screwdriver for the tension. This was not an exercise; we were really locked out!
I’ve been in a similar situation and got in within seconds using an old credit card. The lock in the handle (as opposed to the deadbolt) of most home doors is basically worthless.
I've opened up the front door of our old house before (when I was like twelve? ish?) with a bit of wire I found in the shed; my parents didn't lock the door and the latch on the inside was hook-shaped, so getting in with a wire through the mail slot was pretty easy. I learned it on TV, a segment criticizing that exact type of lock, lol.
Nicely done.
Yes, I have entered someone elses old Honda Civic with my key. Some of them look pretty much alike at first glance.