I think you're probably selling yourself short. I also am a horrible designer, but I've built enough UIs to be able to at least add to the conversation.
I actually consider it part of a front-end developer's job to push back against designs that don't work. There are anti-patterns for users and many of them make life harder for developers (modals launching modals, for example). Some examples from my own life is a designer adding so many columns to a table that it would be too crunched on laptop screens, magic interactions that break a11y, or flows that just don't make sense for seasoned web users. Now that's not to say I can design a great UI on my own, but plenty of good editors can't write a hit novel either.
Most of the time designers are happy for the feedback, because it's cheaper to fix things early on and ultimately makes them look better.
You don't have to be a designer to spot the good and the bad, and I'd be willing to guess you've osmosed more than you give yourself credit for.
I actually consider it part of a front-end developer's job to push back against designs that don't work. There are anti-patterns for users and many of them make life harder for developers (modals launching modals, for example). Some examples from my own life is a designer adding so many columns to a table that it would be too crunched on laptop screens, magic interactions that break a11y, or flows that just don't make sense for seasoned web users. Now that's not to say I can design a great UI on my own, but plenty of good editors can't write a hit novel either.
Most of the time designers are happy for the feedback, because it's cheaper to fix things early on and ultimately makes them look better.
You don't have to be a designer to spot the good and the bad, and I'd be willing to guess you've osmosed more than you give yourself credit for.