The Firefox bug tracker is full of thousands of bugs with some sitting there for 10-15 years. I’d like to see way more focus on cleaning these up than new features and UI changes.
With translations built in, I have one less reason to use Chrome.
There are a few old open bugs, the oldest Firefox bug seemingly being 9 years old, and is about pdf.js not automatically rendering hyperlinks as clickable. There are a few UI/usability bugs in the list, but most old bugs seem to be meta bugs linking several blocking issues, or features being completed part by part.
Firefox may lack engineering power to keep up with Chrome (especially after firing all of those Rust devs), but in terms of bugs I don't think they're doing all that badly. It's not like fixing "Consider to process DOMLinkAdded event using animation frame callback + setTimeout(, 0)" is going to help them gain any market share.
When I tried to look, the results maxed out at 10,000 and the bug tracker stopped being able to respond or sort by date. I wouldn't call 10,000+ "a few" it sounds like you're downplaying it for some reason.
Should releases include hundreds of closed bugs? No. But there could be a couple dozen. Mozilla has the resources to do that. Look at their release notes. A handful of security fixes (good) and otherwise nothing about bug fixes. These are not the release notes of an organization prioritizing software quality.
