Most of what I've seen in the field is either HID iClass (no idea how secure they are) or Mifare Classic. The latter doesn't even attempt to use the card's crypto features (which are broken, but it would've at least been an attempt) and just uses the UID of the card which is broadcast in the clear and even the card's datasheet explicitly warns against using it for any kind of security.
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.
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.
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).