I regularly operate LON to Mexico, Costa Rica etc with just two pilots. Flight time is often 10-12 hours. Add report time and you can see it’s a long day out. These trips are 24 hours.
we do however get 3 local nights off after them.
regularly fall asleep on the fight home. File a report every time and nothing changes been doing it since EASA regs came in 10 (?) years ago.