Настроение:

amused

Final Fantasy 7 Engine Used Staged Modules Instead of Overlays
The game was decomposed into a state machine, and each major state was put into its own executable module with a distinct interface
https://q-gears.sourceforge.net/gears.pdf

That allowed spreading work across several teams, while keeping in memory only the current module.

PlayStation 1 had no MMU, so paging was not an option, and the compilers they used never supported overlays.

Overlays were invented at the dawn of computing, for Cobol and Fortran.
Yet good technology gets abandoned and forgotten in favor of inferior solutions.