Meetings are usually a waste of time because everybody in attendance does not have the same answer to that question above. More so for a recurring series of meetings that happen every week or every month.
When you setup a meeting, be sure to include an agenda on the invite’s mail body. More importantly, try and insist on on a clear agenda before accepting one. Do not accept an invite out of the blue with subjects such as ‘Status update’ or ‘Alignment call’. Your time and attention are worth a thoughtful sentence or two.
If the stated agenda doesn’t concern you, hit that decline button. Your attending a meeting ‘just-in-case’ is invariably a waste of time for all parties concerned.