Hi Fadoua!
No, I don't think Backlog will ever be removed from the Agile process. There are multiple projects/spaces in Jira based on teams and/or products and the work they are doing. So even if you have all of the ideas in a central space, they will go into the individual backlogs of the products/teams doing the work.
Recommended Learning For You
Level up your skills with Atlassian learning
Learning Path
Improve user experience across Jira with global settings
Learn how to set up and configure a Jira site, manage Jira permissions, and configure Jira apps and integrations.
Learning Path
Streamline projects across Jira with shared configurations
Build Jira work items with reusable configurations called schemes, and reduce administrative work with automation.
Learning Path
Become an effective Jira software project admin
Set up software projects and configure tools and agile boards to meet your team's needs.