I agree this was a huge thing missing and am very much looking forward to the Feb 2022 release just for this. There is a work-around that is out there (link below) but it makes much more sense for it to be baked into the product.
It is still quite hard to remove all variables. We can do multiple selections now and hit delete, but we still have to checkbox every single variable, and each page has a max of 15 of them. Deleting 100 or 500 variables its almost impossible this way. Before there was an applet/extension for browser (created by withdave.com), but due new layout it doesn't work any more. I think we are even a worst case than before.
Could you display more than 15 variables per page and add a the select all checkbox on the top? That would help quite a lot!