Strictly speaking, the Sense is bluetooth to whatever you use for a HomeKit hub; in my case it's an AppleTV4K.
If you wish to be picky about wifi vs bluetooth, check out the existing
Schlage Encode Smart WiFi lock. 4.7 out of 5.0 across over 11,000 reviews, 93% 4 or 5 star ratings. The announced Plus version adds Homekit support, as well as the NFC stuff, and I'd imagine would provide similar battery life to the existing model.
So while
you may not see how any battery is going to keep a WiFi deadbolt running reliably, there's a lot of people who've found the reality to be different.
Oh and as for 9V batteries vs a key - I can keep a spare key hidden somewhere for years without worry of it failing.