Yup. All islands, everywhere, are basiclly abandoned, since they’re too small to be effectively protected for how rare giants are. Antarctica is basiclly gone, and the containment zones mean large parts of Asia, North America, and Africa are basiclly cordoned off as de facto sacrifices for the various Mid-Sizes. Stuff on the water’s edge is theoretically protected, but it’s very ‘on your head be it’ levels of risk for those who live there (the spring break parties are even wilder in such places than they are now, since most of the beach goers are to some extent adrenaline junkies); ship based trade has dropped substantially, because out in the ocean is filled with monsters, replace with more air freight and less need to in general because of more advanced technology.
Compared to the current amount of people on land, it’s now closer to 2/3s or even a 1/2, I’d think.