COVID-19 Outbreak Information Updates (Reboot) [over 150.000,000 US cases (est.), 6,422,520 US hospitilizations, 1,148,691 US deaths.]

Actually, many, if not most can and do. There are times of the year when it's all hands on deck and PTO is subject to supervisor approval. If staffing is insufficient, a supervisor has the discretion to reject the request and ask to resubmit for different t dates. Happens occasionally where I work.
When i worked at the grocery dist center, Supervisors weren't allowed to take vacation after Oct 31st. heaviest times of the year during the holidays.