I'm happy to say that my company writes "good" code, at least on the production side, and I have genuinely learned a ton and become a better engineer while working here. The experimental, test, and sometimes CI code is shit. Test code makes sense, it's immature prototype. CI should be much better than it is, it's extremely fail-safe and its false-positive rate is a major headache for the entire software org. But our production code is genuinely very good. You won't get a PR merged with literals in code or custom functions that could be replaced by STD functions or unnecessary copy operations, or without thorough design documentation and comprehensive unit tests and CPU load test results and a review of the effects of your change on near and distant stakeholders. (Our code could literally kill large numbers of people, so it's a good idea to maintain these standards.)

Previously I worked for half a dozen early-stage startups that wrote super-janky demo code that would have to be power-cycled multiple times to get to a fully operational state and no one at the company had more than a year experience outside academia so founders didn't see a problem with that level of reliability. In those roles I learned a lot about math and dealing with giant egos, but not much about software engineering.

Point is, there are companies who rigorously enforce good code requirements, where you can learn from others and improve your skills, where "good code" is the norm.