Jira Cloud customers are not buying a perpetual software license, they pay an ongoing subscription that includes:
When your subscription ends Atlassian will not (and should not) keep your data indefinitely.
This post is a couple of years old, but provides more detail: Contract Termination & Data Deletion.
Hello Atlassian Community! Feedback from customers like you has helped us shape and improve Jira Software. As Head of Product, Jira Software, I wanted to take this opportunity to share an update on...