> Chromium has 63,438 open bugs in its bug tracker so the theory remains true
How many of those bugs affect you on a day-to-day basis? For me, the answer is 0. In fact, I can only think of one time ever when I was affected by a browser bug as a developer. I think that most of the reason Chrome has so many bugs is probably just because a staggering amount of people use Chrome, meaning they can inspect every nook and cranny.
For a somewhat contrived example, imagine I write a program to add two numbers together. I write a single line of code: `var foo = bar + baz;` in JavaScript. If I ship it to no one, I can claim it has no bugs. But if I ship it to a million people, then I might start getting bug reports from people running it under extremely precise circumstances and running into issues. For instance, maybe I'd get a bug where two numbers sum to be negative because the user ran into integer overflow when bar and baz are very close to INT_MAX. I might also get reports of lack of precision when bar is extremely large and baz is not (e.g. sometimes foo + 1 === foo in JS if a is huge). I suspect most bugs in Chrome are of this variety, or, more likely, they are even more obscure.
It seems to me that it's not a strict 1:1 correlation between size and quality - there's also a factor where more popular software has a lot more people looking for bugs.