Is anyone else not a fan of the 4/80 work schedule?

I worked at a firm on a team of 3 people for cad/gis stuff and my manager had the 4/80 schedule, including during my first week on the job. I often felt them missing every other Friday was hurtful for the team of THREE people 😩. One time they were out and my other teammate went on pto without telling me, causing me to be the only person on that team for the day which was not fun. Maybe if the team had more people I wouldn’t have an issue, but when you need your manager for something and they’re not available not really the greatest experience.

Do most firms have guidelines for allowing people to have a 4/80 schedule? I don’t even think my manager worked 10 hours a day tbh.