> I don't know how much more cost effective AI bots are for customer service over offshore call centers currently

They are already fairly cost effective. A the Corporate VC arms of the major call center and BPO players like Infosys, TCS, and others have already funded a large portion of TTS startups, and in a lot of cases are training on customer calls.

There's a reason ElevenLabs, Deepgram, and others are the giants they are now.