Yes. And the resulting churn and dissatisfaction is mostly invisible, unless you go looking for it. Most users don't even file bug reports when things are actually broken. Most users can't tell why they don't like something when it just runs slowly. Even technical users will almost never file bug reports against slow and janky performance.

I hate Jira - but I think the main reason is just that it feels slow to use. A slow UI gives a visceral felt sense of lethargy / sickness, which I associate with the product. Is that a bug? I don't know. But I bet it runs fast enough internally at atlassian. And I suspect the PMs at atlassian tell themselves the same story - that its not worth the development time to make it fast. And that might match with the feedback they get, because all the users who care about that have probably already bounced to other products.

Jira is bad for a completely different reason. Jira is bad because Atlassian has grown from a company that sold software to its users, to a company that sells software to people who work in corporate procurement. Atlassian only has to impress two people to make a sale now. The person box ticking the features, and the person who wants to see the reports that it produces, and neither of those people are the ones who actually use the software.

I worked at a company where they used a time tracking application (most of their revenue was T+M) which was so bad that one of the developers reverse engineered the front end API and built a new front end for it.

What you said about impressing the person viewing the reports really rings true in that case.

I think my rationale applies to client side code too, just in a slightly different way. It is so easy to write performant browser UIs these days, and a lot of that is down to these same sorts of hardware improvements (as well as V8 improvements). Even bloated web app front ends will perform very well most of the time. You can take that to the extreme of course, but you really have to go out of your way to do it.

I’ve built frontends before without giving any consideration at all to performance, and they’ve always performed perfectly well. Websites like cnn.com exist, so it is demonstrably possibly to do it badly, but you have to stray so far from the light accomplish something like that.