From what I'm seeing, most of the people asking are artists and musicians, and the apps they use are more RAM-hungry than the OS itself or the bundled Apple apps. However, I'm not sure what specific apps those are. Maybe they're ports from Windows, and their iOS-native competitors can make better use of GPU and ML hardware acceleration APIs, since those seem to be strengths of the A14 SoC.

It's relevant for browsing with multiple tabs. The more RAM you have, the more you can do in other tabs after switching away from a tab without having that tab reload when you return.

It's very annoying if you were somewhere in the middle of a long page, go to look up a few things on other sites, come back, and your original tab reloads and you are back on top.