I've used JIRA at multiple workplaces and really enjoy it. I like Github issues and Trello for my personal task/issue tracking but I don't think they're suitable for more complex projects.
In this thread there's people saying that inability to host on prem is an absolute blocker for them, for others they have zero problems with their data being SaaS-hosted. Some people need deep analytics to measure how their team is doing and they can meet deliverables, and some people could care less. Some people have 10+ workflow stages with tons of rules, some people are fine with Todo / in progress / done.
If you have a small team and dont really care about reporting, Trello is probably a great option for you.
If you want reporting, but are willing to work with a somewhat prescribed workflow / process, across a few teams at most, clubhouse or pivotal tracker are great.
If you need full control and flexibility, and are willing to give up some ease of use and speed, JIRA probably is your best bet.
JIRA sucks, but it sucks compared to more lightweight tools and the modern aesthetic
It outperforms previous tracking tools like bugzilla, trac, or those proprietary piles of crap like the "Rational" tools