A queue is a different object from a ring group because waiting is a different problem from ringing. The hard questions are all about the caller who is not being answered: how long they wait, what they hear, and where they end up when waiting stops being reasonable.
What the call does
Every queue requires an overflow destination and a destination for when no agent is logged in. You cannot save a queue that drops a caller into silence.
Being in a queue is a state, not a permanent property of a person. An agent logs in when their shift starts, and the queue knows the difference between nobody available and nobody there.
Each queue links straight to its own filtered report: answered, abandoned, average wait, longest wait. Nobody goes hunting in a separate analytics product to find out whether the queue is working.
Drawn, not filmed
The call reaches the queue, holds its place in line, and goes to the first agent free.
Most people never open the second column. It is one click away rather than spread across the first.
On every plan
This is included whichever plan you are on, with no add-on and no module to enable. Plans differ by how calls are distributed and how long the history is kept.