One equivalent that does everything and is as flexible as jira, I don't know.

There are however a multitude of software that provide some of the functionnalites or can do many things jira does but in a more opinionated way.

It depends if one's company want a tool flexible enough to suit gazillons of different workflows with integration with many other tools or not. If the goal is only to have issues and kanban boards I think there are many alternatives.

Funny thing is jira is such a mess Atlassian introduced jira service desk more focused on tickets while the former can also do that.