"My project isn't open sourced yet" underlines the problem. There has been a massive explosion of software that works, but badly. The average user experience suffers as a result.
Most of proprietary software is just crap, and always has been. The agents are not producing worse code than typical, demotivated, i-dont-care-what-i-am-building-i-wont-try-using-it corporate development teams have over the years. I'd even bet that because now making changes and fixes is so much easier, the user perceived quality will trend upwards for popular stuff.
The code itself may or may not be spaghetti. Not that I care as a user. User experience and code quality had never a particularly strong correlation even before AI.