So people probably don't worry about cost-effectiveness of their home security system, they just want to feel safe in their home.
Of course, there are security benefits if you have a cleaner/dog walker/whatever and want to give them access you can revoke without the cost of changing your lock. Or if you're running a commercial installation like an office or AirBnB.
Still, I don't think electronic door locks will become mass-market until someone makes one so reliable it doesn't need a mechanical bypass key, which might be impossible.
I’ve seen hotels and student dorm rooms using insecure systems (the latter of which I exploited as a teenager to make a second keycard to sneak into my GF’s room without having to borrow her only key. How easy the attack was worried me quite a bit).
Of course, the best bang for your buck is still the simple stuff - a few motion detecting lights, some security company stickers and a clean, well-kept yard.