> I remember using a computer with RAM measured in two-digit amounts of MiB

Yes, so do I. It was limited to 800x600x16 color mode or 320x200x256. A significant amount of memory gets consumed by graphical assets, especially in web browsers which tend to keep uncompressed copies of images around so they can blit them into position.

But a lot is wasted, often by routing things through single bottlenecks in the whole system. Antivirus programs. Global locks. Syncing to the filesystem at the wrong granularity. And so on.