I get hundreds of packages per year (not an exaggeration) and as far as I know, exactly zero have ever been stolen. Missing packages are invariably delivered to someplace else that must have had a better vibe for the driver that day. (I’ll get pics of proof of delivery with a package that is clearly not at my house.)
In that environment, what problem do I have that could be solved by this, how much effort (and aesthetics) am I willing to spend to solve it.
Now, if my house shared a wall with two other houses and people walked by my front door all the time, maybe I’d have a theft problem due to greater opportunities for it to happen.
Places with lawns probably don’t have nearly as much package theft just due to less foot traffic.
When this happens you have to go to a post office to get your mail.
I suspect that some of the the same reasons that lockers aren't economically feasible in most of the US is the same reason that the theft isn't a problem: low density. If you're a porch pirate, you need to expect that the value of your stolen goods covers at least your gas and time driving around stealing stuff, plus some risk premium for doing the crime. If the average value of a package is below this amount, the crime doesn't pay. There will still be instances where people haven't done this math, or crimes of opportunity, or just dense stretches where it does make sense depending on the price of gas, but it isn't a nationwide problem.
I agree that per-household lockers are... tricky at best. But then, if we're talking homes, and thus presumably lawns in front of them, I wonder what are the difficulties of selling a multi-slot locker that would be bolted down to the ground (or perhaps a bunch of concrete filling a hole in the ground), and thus as easy to steal as a thick fence post or an ATM? Is this too expensive for homeowners?