Yeah, it's an easy way to make a sort of foolproof method when you have little control over other variables. When you're doing any kind of extraction from a solid to a liquid there's basically three variables you can play with: temperature, time, and surface area. If you choose go for a longer time and get roughly the same amount (not the same flavor necessarily) of extraction, then either lower the temperature or use a coarser grind size. With immersion brewing like french press (or aeropress to a lesser degree), the fluid dynamics are almost negligible, unlike espresso or pour-over, where the way the water flows through the coffee bed affects the flavor a lot.

So yeah, keep your coffee brewing for a long-ass time in order to get better extraction. My only issue with the James Hoffmann french press method is that my coffee is almost tepid by the time i get to pour it