Currently the lists and filters and groupings give no indication of the amount of items they contain. Such insight is very often needed and I see myself counting items manually, which is a tedious thing for long lists.
Think about for example the amount of 'agenda items' or 'attendees' or 'sold items' ..anything requires insight in the totals.
I think the absence of totals was based on the initial idea of 'tasks only' in Clickup. We are far beyond that at this point, and custom item types to replace tasks are already planned.
ideally, the whole display of lists and filters should be improved in order to allow display features to be turned on and off by users.