Given that Fermilab employees over 2000 people, people's experiences range wildly. In my case, I was placed in a role that couldn't have capitalized more poorly on my experience and skills. The truth is, almost everyone new hired at Fermilab is overqualified and underpaid for their positions, guaranteed by the strict and cumbersome regulations that the Department of Energy Office of Science imposes on this beleaguered and top-heavy National Lab. Its best days are behind it.
If time isn't valuable to you, Fermilab may be the perfect fit. Even the most mundane and matter-of-fact decisions take weeks to finalize and months (or years) to purchase with their broken procurement system and opaque and paradoxical budgets. You'll find even the lowest levels of Management plagued with Zoom meetings almost every hour of every day, with little to no time to actually supervise their group or even contribute to their subordinate's development.
Even technical positions are best characterized as a 20/80 split between actual work and writing procedures, reports, requests, or waiting for something to happen. My supervisor did a stellar job at being a slow, discouraging and excuse-making contrarian that did his best to hold the department back as long as it meant he could keep consolidating the technical aspects until his role. Fermilab will turn even the most optimistic and forward-looking ambitious individuals into slow-speaking risk-averse bureaucrats terrified of trying anything new. And if you so much as reach out for help or explanations outside your immediate group, there will be snitches to undermine your good-faith communication.
Maybe your experience will be different, but Fermilab is no place to build a career or make friends if you already come with experience in the Private Sector.