You’re comparing database to a trust-less distributed fault tolerant system. Of course the db has a smaller energy footprint but it doesn’t provide the same features. It’s like saying a bicycle rolls down the road just as well as a car so we should not use the car.

There are blockchains now that are designed to be optimal for what they provide.

The bigger issue is that there are applications running on chains that clearly don’t need the features of the chain.