Am I missing something?

Four to five hours... is that after the "slop" or before? You know, touchdown, taxiing, deplaning, hikes (hello Swampy), security, travel times, being there to board when they start boarding... Last flight I took, that 380 spent 15 minutes taxiing after touchdown, looking for a parking place... even the stews were rolling their eyes... then waiting for everyone in front to deplane (back of the bus rider here). That 90 minute layover translated to 20 minutes in the lounge, and there were NO lines at transit security, and the gates were close...

If you're waiting for an international connection, you leave the transit area, that means immigration, customs, then return for immigration, security... Having never laid over in Manila, can't say if there's a security check between arrival and departure flights like Korea, but IME at other airports, perhaps less lines for "internal" checks than outside departing checks. I just kick back in the lounge, have some food and some rehydration. The hassle just not worth it. Now if it's an overnight layover...