All security is an economic equation. All of it. Anything that increases the overall time/energy cost for an attacker represents an increase in security. Security is also heavily defined by lowest energy failure points and the human interface cost/benefit factor (because security itself often takes time/energy, so there's no point in expending more then whatever is being guarded is worth). In this scenario, both come into play in a way you're not giving credit to. I can't speak to your situation, but large numbers of us do not live in heavily armored homes packed with alarm systems. The door lock is essentially a mixture of minimal energy cost/social message ("nobody is home and you are not invited to just wander in") and a canary system (if someone does break it, it'll be obvious it happened).

It's become trendy any time someone mentions biometrics to talk about "finger prints being everywhere" and all that, but it's always incorrect to do so in a security discussion without considering overall economics. The fact is that, at least for now, it is not trivial to find, lift, and duplicate a fingerprint to the level needed to fool a decent reader (ala Touch ID). Long before it's worth doing that, a typical crook would simply break a window (including a door window should any exterior door in your entire house have any glass) or, likeliest of all, simply go to another house. Much of the low level crime that takes place is because a crook is interested in getting someone, not you specifically. It's a numbers game, it's not worth it to go to a lot of effort against one somewhat more secured building when the one next door may be wide open. Conversely, if you're subject to an actual persistent targeted physical threat then you've got vastly bigger problems then most are equipped to easily deal with. You have to make sure keys don't get stolen/duped, that hidden cameras aren't installed, that professionals can't pick or use more advanced subtle physical bypasses, etc etc.

Finally, it's necessary to compare to what the actual practical alternatives currently in place are. "Key under the mat/behind the flower pot/fake rock on lawn/..." or some variant is how a huge number of homes currently deal with fallback entry. Even if in general a copy of keys are carried around, being able to get into one's home no matter what is important enough that many people will at keep least one copy on premises in case they forget/lose theirs or a guest needs to get in or something. That's not a high baseline to surpass.

So there's nothing inherently wrong with using biometrics in scenarios like this. They're convenient, audit-able, cannot be lost or forgotten, and are often at least as good against expected attack scenarios as what currently is in place. There are certainly ways to make it even better, or promising alternates. Using a different factor (like a pin or electronic) key as the primary option with biometric fallback (in an electronic system fallback usage could be used as a trigger), time fencing, combining it with another option for MFA, or in the future directly improving "something you are" (such as with implants) all could be considered. But right now it's perfectly appropriate security for many homes. If anything my major concern would not be security but rather reliability, so I'd never use it exclusively. But it's silly to just write it off purely because it could be bypassed with sufficient time/energy/expertise.