The desire to connect every single thing to the Internet is a complete waste of resources in exchange for profound security issues and mild reliability risks. Use a key. It's the right tool for the job.
I'm not convinced it is even lazy to use a phone to unlock a car.
Not sure the reliability risks are that mild in this case. Phones can run out of battery. I would not want to be locked out of my car in the winter because I ran out of batteries and looking at my car which both can charge it and save me from the elements.