PTO accrual: you have a PTO balance, which you can spend as you wish and which is filled by a certain number of PTO hours each pay period.
Mandatory 4 weeks: you have to take 4 weeks off each year. You cannot spend your PTO as you wish.
In my case I don't have accrual, my PTO balance is reset every 1st of January, if I have any days left, they are "gone". I get the same balance of Jan 1st if I had 30 days of PTO on Dec 31st and if I had 0 days. It's not ideal but still is better than mandatory time off as I still have a choice to let the PTO "burn".
As far as me being an outlier I think you just get industry experience from reddit and have not worked much. Wherever I worked managers sent emails with dozens of names on the cc: regarding PTO balance reaching cap, there were always giant threads whenever HR posted about PTO cash out or cap change polices etc. If people starved for PTO that would not have been happening.