I use Jira with 300+ users for both software and non software projects. I don't love it for either but I don't hate it enough to move. Any tool that offered 1:1 feature parity and a full migration, would only need something as simple as slightly cheaper or faster for me to move. IMO the administration is a pain even for simple things.

I've also been on Jira for at least 4 years now and the development is just sad... New UI stuff wasn't "better" just different. Pages are still slow if not slower. Reporting is abysmal; we use the API to pull pretty much all data into a database and report from that. The one tool our team's universally loved was canned– a browser extension that allowed you to screenshot and open ticket with things like browser info and URL already in the ticket. We even tried to modify the extension to put metadata from within our application (didn't work and product was sunset anyway).

My outlook is that developers will move towards something like Jetbrain's issue product or maybe even GitHub issues someday. Support teams will move towards a more dedicated support style system like zendesk or a custom solution around twilio. And for non dev projects, I hope better tools come up... Microsoft project seems to still be a leader in my industry, and also seems to be universally hated amongst my teams.