TDD gets pushed because it creates great, easily trackable metrics one can gesture to as evidence that a) your code is good and b) that you're doing a good job and should be paid more.

It makes developers happy because it translates the somewhat arcane nature of the work into something easily digestible by management, and is a fig leaf for shoddy work.

It makes management happy because it goes nicely on a chart that can be shown to the director/customer/shareholders, and looks good at status meetings. It also gives them something to poke at and micromanage.

It makes the customer/shareholders happy because it provides a metric that their money is being spent _doing something_.

TDD may have started as a coding best practice, but it exists and endures - and will continue to exist and endure - because it's performative, and the performance has value to every layer of a business, even though it has nothing to do with actually making the product better at this point.