if you are not using 7day skdl on your very large AC then you will be dead in real GWs.
This.
My last serie of 7 B777 is flying 19.7 hours per day. And, despite matching demand, is just barely making profit(counting staff, return on investment, marketing, etc.....). For those who don't know what 7-day schedule, each aircraft has the same schedule - just starting another day. B777 number one flies so :
Monday KDTW - RPLL 07:45 - 14:05 RPLL - KDTW 16:35 - 20:25
Tuesday KDTW - YBBN 22:55 - 08:35 YBBN - KDTW 11:05 - 15:15
Thursday KDTW - NZAA 19:45 - 06:00 NZAA - KDTW 08:30 - 09:10
Saturday KDTW - PGSN 11:40 - 18:15 PGSN - KDTW 20:45 - 20:45
Which leaves around 10 hours during the night from sunday to monday for the A-check.
The next plane does the same, but flies to Manila on tuesday morning, the third one on wednesday morning, etc... A brand new 777-8X costs in 2027 around 500M$. You must have it in the air all the time not to lose money.
If I flew only one destination per plane, I'd need 8 B777 instead of 7, and I'd fly only 6 days instead of 7. At the price of long-range aircraft, I'd be broke in no time. I'm flying 4 flights per week instead of 3 - that's a 33% increase in revenue.
All players alive in real game worlds do that - or avoid long range completely.