You aren't the only one. There are many people using Github Copilot.
Github Copilot CLI is for automation. For example, in a Rust project, I use it to audit for security, documentation gaps, and test issues crate by crate. This can take an hour and I look at the suggested stories it writes afterwards to triage for implementation.
And does Copilot CLI make that more convenient than letting the Copilot Plugin in Agent mode do it? Maybe because of swarms of agents?