I had a partner organisation insist on Jira for their project a few years back. It'll obviously have changed since then and much might be down to user-specific customisations, but I hated it. Awkward, obstructive, poorly thought out workthrough that mostly involved jumping through hoops and provided us very little actual value.

My main memory actually was of poor fit and finish. Just a tiny thing but every time I logged in, no matter how, it offered to remember my login. Every time, I clicked that box in hope. It never once worked.