> Do startups produce shining examples of high-quality code?

Presumably this is about the quality of the end software, not the code that feeds it. some classes of startups are certainly known for attempting to improve quality apparent to the end-user over market leaders. Some even succeed.

For the most part this isn't hard compared to "big tech"—just strip out the enterprise-oriented crap and ads. The hard part of making a business writing software is profiting off it without destroying it.