There are a ton of people who _immediately_ open tmux/zellij/etc. when they're doing anything in the terminal. This means you use its backscroll and search feature, and you wouldn't notice.
@mitchellh seems to rely on the Ghostty feature to dump scrollback to a file, and edit/search over that.
I found it a bit too inconvenient when using remote systems frequently, though. (If I'm missing a trick, I'd love to use Ghostty! But I'm just not a fan of multiplexers.)
My use cases are trying to find the one test that failed out of my suite and finding a specific log print when my app is running. Yes, there are other ways to do both of these. Having scrollback search in the terminal is a very convenient option though.
Honestly, I had never even heard of it before this very thread. It doesn't seem all that useful to me, but I don't truthfully know how much or how little I would use it in practice.