Earlier quoted context omitted.
If you think that's a perk you don't belong doing that work. It's not the james bond life you think it is and the people who think of it that way are insufferable. Try living in a windowless box for 8 hours a day and having no resume.
I think you meant the inverse. If you value optionality to work on government projects that require clearance wouldn’t one view already having said clearance as a perk? If you don’t want to do that work you would not view it as a perk.
I can only speak from the contractor side of things, and it is true that many job openings list "must have active [clearance X]" as a requirement, which certainly keeps the candidate pool to within people already in that community. It takes 12-24 months to get some clearances, with no guarantee that after that time invested, you will actually be approved. So it is a massive gate.
But the flip side, as others pointed out, is you have large chunks of time where you cannot talk about what you did in anything approaching the detail someone who worked on a non-cleared job can. Even if you worked on some stealth mode startup's top-secret project, with NDAs and whatnot, there's nothing like the very real threat of decades in federal prison. The best way to avoid falling afoul of an unauthorized disclosure is strongly compartmentalizing your work life - this is strongly encouraged within the industry. You talk about work at work, in a vault where the only other people there are cleared. You STFU everywhere else. Easy and simple to remember. The only time this is _ever_ a problem is when you're trying to get out of the industry, where you must talk about your work experience to potential employers. That's how your perk becomes a trap.