The main reason people still use degrees is because the majority of the population only know degrees, can't be bothered to change, and the majority of the population will continue to only know degrees, unless radians start getting taught at a much younger age.

People can't be bothered to change, except radians are much more mathematically easy to use, so people who need to do advanced maths will use it.

However, laziness is also the reason why people don't change to tau. tau is just a multiple of pi. Confronted with such a small change, people will just think that they can't be bothered to change, especially since pi is already widely supported and implemented in any of the tools that we use, and tau is not.

There's no way that changing to tau will make more people use radians.