When you're considering a new job, one of the things you'll find out as part of the package is how much vacation (or PTO, "paid time off") the offer includes. The US doesn't do as well in this regard as some other parts of the world. In tech, you can probably expect two to three weeks of vacation days per year plus six or seven designated civil holidays. In some companies, after you've been there several years you earn more days per year. (At my current company, after five full years I started earning one extra day per year.)
Next time I consider a new job, I have to remember to ask not only how much PTO is included but how much of that is actually mine. It's not mine if the company says I get X days but that I have to allocate some of them for Christmas week "because we all need time then to be with our families". That would be patronizing and presumptuous even if Christmas were my holiday! It's not, so that makes it even worse.
It's fine if an employer says "we're closed that week for business reasons". Sometimes companies do that. But in that case, they should either grant those days (as if they were civil holidays) or reduce the PTO claims in their job ads and HR policies. I use several days per year for my holidays, ones they don't grant, plus (in non-pandemic years) actual vacations that I choose. I would like employers to tell me the number of days I really have, the number that are my choice.
When I joined my current company I was told how many PTO days I get per year. Later, they started declaring mandatory shutdowns for Christmas week. I can use my vacation days or take the days unpaid.
Retracting vacation days, which is what they do when they say I can't use them freely any more, is akin to cutting salary (as is saying "then take it unpaid if you didn't save vacation days"). Employers, be honest about that: you're reducing my compensation. Do not pretend you're doing it for my well-being, for my family time, for my holiday -- you're not. How valued am I really, if you reduce my compensation so casually?
I've always found the last week of December to be a great time to get work done; I can focus on things that keep getting pushed off or interrupted, because there are few or no meetings and other interruptions. Meanwhile, I can use those days for my holidays. Everybody wins.
Companies should actually consider giving top employees more vacation days, rather than only the tenure-based allocation. When someone consistently performs above the norm, then not only should you reward that, but you're still ahead of the norm if the person takes that time off! Employers, please start considering PTO increases as part of the mix that includes salary increases, bonuses, and assorted perks that people use inconsistently.