In older versions of SharePoint, we used to be able to close web parts. I really miss this functionality.

We sometimes create content that is only relevant for specific periods, e.g. for an annual event. We'd close the web part when it was no longer relevant then reinstate when next needed.
It would be great if you could find a way to reintroduce this functionality, but I understand it may not be possible given how and where web parts are stored.