JiraCLI seems to spend most of its code budget translating in between CLI args and JQL; that's the easy part.
Because every org uses Jira differently, it seems hard to write a generic tool that works well with your org.
This lib is maintained, still a bit out of date and has a few flaws. Like using the same client for JIRA Cloud and JIRA OnPremise (different APIs). But most of the flaws have been evolved over time, while Atlassian switched strategies.
I am preparing a roadmap for v2 where I implement a lot of reliability features, like context support, but also separate APIs for OnPremise and Cloud and easier access for custom fields.
Watch the github repo if you want to stay up to date.