It reads your other code so it can match the style, it runs the compiler, if any, it runs the tests, and if anything fails through any of it, it handles the errors and works on it.

If you ask it to, say, update the major version of some library, it will read the source of the new version, check the deprecations, attempt the changes based on that, rerun tests... a completely different level of utility.

It's even more ridiculous with access to server logs and such, as you can point it to a chart, say there were some errors in X service at Y time, and it'll dutifully look at logs in that window, check traces if available, look at caller services, check the database if needed, and come up with a hypothesis on what happened based on all the available information. It might miss things, but that's why you are there too. No need to be a prompting wizard that gives it everything it needs to get you the right answer in one shot: It's like pair programming with someone that has encyclopedic knowledge in many topics, but hasn't worked at your company before. A completely different experience.