Any manager who was waiting on the "data" (read: sponsored study) that you need to invest in proper tooling for your devs isn't going to do anything significantly different because of it.
The job of a manager is to make good choices and decisions. In the absence of an obvious best choice, they have work backward from both success and failure scenarios, including the political and social impacts.
In the absence of external studies and data, if they make an investment in this area and it turns out not to help, they will be left telling their boss things like "everyone says this is right, not sure why my project didn't work."
But a flimsy fig leaf that comes from outside and smells objective is a perfect CYA tool that allows the manager to take a risk while anticipating the need to manage and contain failure.
Does that describe a healthy dynamic and a smart organization? No, but it's reality at many places.
For example, what if an engineering manager needs to convince finance for headcount to hire a devex employee?
If you read the introduction of the paper, you'll see that the aim of this paper is to give managers and developers concrete data to use to help get buy-in on investing in developer experience from business leaders.