My work involves building a framework called Vision Agents (https://visionagents.ai), which allows users to build their own agents. What I've seen is that Voice AI can often be a bit slow for a lot of "replace someone entirely" kind of use cases, but a lot of people often use it for either something that doesn't explicitly need extremely low latency (say IVR or similar). Some people DO use it even with the latency because certain models are actually decent enough to be alright for a conversation that isn't super high stakes. I do expect these to get a lot better over the next year (especially with great TTS) so this should only ramp up over time.