Strong agree. School had me writing stuff myself on the order of a few KLOC at most, and maybe collaborating with a "group" in which at most 2 people actually did anything. What little exposure I got to reading a large codebase I didn't write, was all in personal projects trying to mod open source video games. I'm sure some people had more extensive experiences but that was my bachelor's.

First job had me using a programming language I wasn't super familiar with and trying to add a feature to a codebase 100s of KLOC, all written by other people. Definitely a sink-or-swim moment. My skills of reading and navigating the dreaded Other People's Code were all honed over the next dozen years.

That being said AI is a lot better at reading code than I am, as demonstrated by its ability to find incredibly subtle bugs in huge codebases. So I'm not even sure those code reading skills are all that useful now. When I have to review somebody else's code I get more mileage from pointing an AI at it and asking targeted questions like "how does this handle when a Foo's approval is revoked" than reading it myself line-by-line. I'm not saying I never use those reading skills but the ability to get the big picture, chase down deep callback chains, know where to look... those skills are likely to atrophy.

It's like using GPS vs. knowing the roads as well as a cabbie. GPS gets you pretty damn far for zero effort.