Seriously, ask yourself, how often did the need arise to look into old commits

Literally every single day. I have a git alias that prints out the commit graph for my repositories, and by looking at that I can instantly see what tasks my coworkers are working on, what their progress is, and what their work is based on. It's way more useful than any stand-up meeting I've ever attended.

I've been in the industry for a few years now and I can literally count on one hand how often I had to actually look at commit history for more than maybe 10 commits back.

I've been in the industry for nearly 15 years, but I can say that the last 3 years have been my most productive, and I attribute a lot of that to the fact that I'm on a team that cares about git history, knows how to use it, and keeps it readable. Like other people have been saying, this is a self fulfilling prophecy - most people don't care to keep their git history readable, so they've only ever seen unreadable git histories, and so they think git history is useless.

I honestly don't see a use case that would justify the overhead.

What overhead? The learning curve on rebasing isn't that much steeper than that of merging or just using git itself. Take an hour to read the git docs, watch a tutorial or two, and you're good to go. Understand that people actually read your commit messages and take 15 extra seconds to make them actually useful. Take an extra minute before opening an MR to rebase your personal branches interactively and squash down the "fixed a typo" and "ran isort" commits into something that's actually useful. In the long run this saves time by making your code more easily reviewable, and giving reviewers useful context around your changes.

It's always just "but what if X, then you'd save hours!" But X never happens or X is caused by a fucked up process somewhere else and git is just the hammer to nail down every problem.

No, having a clean, readable git history literally saves my team hours. I haven't had to manually write or edit a changelog in three years because we generate it automatically from our commit messages. I haven't had to think about a version number in three years because they're automatically calculated from our commit messages. Those are the types of things teams sink weeks into, time absolutely wasted spent arguing over whether this thing or that is a patch bump or a minor bump, and no one can say for sure without looking at diffs or spinning up multiple versions of the code and poking it manually, because the git log is a tangled mess of spaghetti with meatballs made of messages like "finally fixed the thing" and "please just work dammit". My team can tell you those things instantly just by looking at the git log. Because we care about history, and we keep it clean and useable.