The only take I'm gonna have about Buttigieg as Transport Sec is that when you have a sector as cost-disease-ridden, ineffective and inertia-bound as American transportation, an insider with decades of experience in the system isn't necessarily the ideal pick.
Countries that are stuck in the mud often do very well by finding sharp, bright young outsiders who aren't afraid to slay a few sacred cows and putting them in administrative roles: Dengist China, 19C England, Singapore.
Which is to say that Buttigieg will assuredly be imperfect and may well be a total dud, but we've seen this year what happens to Trusting the Experts when the Experts are so far up the ladder of expertise they can't see the forest for the trees