> I've never seen an hotline where you can call back and resume the call you were doing.

Assuming they even accept inbound calls to the CLI number in the first place.

I frequently encounter companies where I miss a call due to $reason, I then try to call back the CLI number and it just says "This was $megacorp trying to call you, we will try again later".

Or, if you're really lucky, the CLI will just dump you into IVR-hell which, of course, is "AI powered" today, so you have to spend 30 minutes telling the stupid robot they mis-intepreted your voice.