(unlike his boss)
"After you've run NASA, to go from doing this to whatever I do next is going to be really hard," Bridenstine said. "This has been the greatest experience of my life by far, and I'm so grateful for it. But I am under no illusions. There are a lot of people that can do great work as the NASA administrator."
https://aviationweek.com/defense-space/space/nasa-chief-plans-step-aside-under-biden
Bridenstine has relished the challenge of leading NASA through troubling times and overcoming initial concerns about his partisanship to lead NASA—all of NASA—through the turbulent years of the Trump administration. Nor is it because he has failed. Bridenstine has largely succeeded in pushing the agency forward and will leave it better than he found it.
https://arstechnica.com/science/2020/11/jim-bridenstine-is-leaving-nasa-how-should-we-assess-his-30-month-tenure/