At that rate and assuming 4tx per second a single Bitcoin transaction consumes 165kWh. A Tesla battery is bit over 50kWh. So let's round that to 3 full charges of Tesla battery. That's 350km/220 miles of range per charge. In total 1050km or 660 miles of driving. So basically if you want to transfer money and the recipient is closer than 660 miles from you it's more efficient to just get a bunch of bills, drive there…
The team that works on it isn't interested in making any upgrades. It's pure religion at this point. They would argue that a chunk of the energy is renewable -- so that makes it better.
There are many upgrades that have and are happening, some examples: segwit, schnorr/taproot, lightning network, etc.