I agree with this. OP, if you have 2 way sync between JIRA working already, then why not let the product folks keep using JIRA as they like and make a new approach that engineers can love and adopt without forcing the entire team to switch? Basically an engineer-driven front-end for JIRA. Focus on viewing/searching, allow the UI to be hackable/customizable on a per-user basis, etc.

Currently, you’re not competing against JIRA, but rather Asana, Basecamp, Trello, etc for customers. While not rational, a large part of their appeal is they look nothing like JIRA, which can’t be said for you.