I'm using Jira for years. It has always been slow, never -ever- seen a fast Jira, no matter what machine or internet connection. Just loaded our company's dashboard:

That display shows the heaviest network payload for a web app I have never seen. I don't know what kind of a technical debt this project has but come on, this is a 3D rendered game and it is lighter:

nav[aria-label="Primary Navigation"] { padding: 0; & ul { list-style: none; width: 100%; display: flex; flex-direction: row; justify-content: start; align-items: start; gap: 30px; padding: 0; & li { margin: 0; } & ul li { list-style: none; } } }