I work as a frontend engineer and used to think similarly. I don't think I encountered any browser bugs for the first few years, as I was mostly just wiring stu

I work as a frontend engineer and used to think similarly. I don't think I encountered any browser bugs for the first few years, as I was mostly just wiring stuff up and wasn't taking advantage of newer APIs. But eventually I started trying out newer APIs, and I would occasionally bump into weird and unexpected behavior. I was always convinced it was my own fault, but after countless hours trying to debug why something was behaving oddly, I'd look up a few keywords and usually found bug reports in each browser's issue tracker. Browsers are incredibly complex pieces of software which are constantly evolving. Go look at any browser's issue tracker and you'll find a huge list of bugs.