If there was an application of windows that users rarely used was Cortana. So Microsoft is removing the standalone Cortana app in Windows 11.

Microsoft had reported that the Cortana will no longer exist as a standalone app in Windows 11. Two months later, Microsoft removes the Cortana app through an update in the Microsoft Store.
However, only Windows Insiders following the Dev and Canary channels will receive the update for now.
Cortana will likely stop working on the other Insiders channels in the coming days as well, and finally, it will stop for everyone later this month. We don't know if the app will still be present in the upcoming Windows 11 23H2 update, which will likely be released in September or October this year.
Upon opening the app after the update is complete, users see a welcome message that says: “Cortana on Windows as a standalone app has been removed.” There's also a Learn More button right below the message, and if you do click will take you to the Microsoft support page that describes how this change will affect users.
According to Microsoft, the change only affects Cortana on Windows. Cortana in Outlook Mobile, Teams Mobile, Microsoft Teams, and Microsoft Teams Rooms will continue to exist until the company decides to retire those versions as well.
Microsoft already has it Windows Copilot to replace Cortana and become the central AI assistance platform for Windows 11. Although Windows Copilot is still not as good as you would like, it seems to be much better than Cortana.

We had turned it off manually