I get the spirit of what you're trying to say (I think) but the truth is that wireless spectrum is an extremely scarce resource. It is bad policy to let inefficient protocols use it without good reason - 2G has the status of "lowest common denominator" and that's probably the only baseline that you should be able to rely on.

There are a ton of other inefficient allocations of spectrum^1, but not all spectrum is suitable for all purposes and the bands for cellular connectivity are highly sought after.

1: https://upload.wikimedia.org/wikipedia/commons/c/c7/United_S...