I had a similar experience at a startup where I'd never used any PTO endlessly burning at both ends.
A few years in, executives abruptly told everyone they were switching to "unlimited PTO" and everyone's accrued PTO would be erased "since it's no longer necessary, take as much vacation as you want."
Sales/marketing depts celebrated.
My team in engineering flipped out since none of us had ever used any PTO, and knew there were some sizable checks waiting for our exit. I ended up telling leadership if they pull this erasing shit, which is probably illegal, I quit immediately and will be in tomorrow to interview and renegotiate compensation if they like. Everyone received checks for their unused PTO that week.
They still switched to unlimited PTO, which us in engineering never really got to use. In a startup it's a race against the runway running out while you're still building the plane, nobody has time for PTO, and they knew this.