Evidence since mid‑2024 shows a clear wave of AI adoption specifically in phone-based customer support, matching Sacks’ prediction about where AI in support would “go next.”

• Numerous vendors now market AI phone agents / voicebots explicitly as IVR and call‑center replacements, offering natural, multi‑turn conversations over the phone (e.g., Air AI, Insighto.ai, Five9 IVA, Talkdesk AI, Callin.io, Phonecall.bot). These platforms emphasize handling inbound and outbound calls, appointment scheduling, order support, and triage—functions traditionally done by IVR trees and human call‑center agents. (siit.co)
• Industry and vendor blogs in 2024–2025 describe AI voice agents as a major new wave in contact centers: replacing rigid IVR menus with conversational agents and positioning AI receptionists/phone agents as a replacement for traditional call centers, especially for SMBs. Articles talk about AI voice receptionists “replacing traditional call centers” and AI phone calls becoming the “new normal” in 2025, with SMBs and enterprises deploying these agents at scale. (blog.peakflo.co)
• Contact‑center commentary notes that voice remains over half of all customer interactions, and AI is increasingly applied specifically to voice to make calls feel like natural conversations instead of menu trees—exactly the IVR‑to‑AI transition Sacks described. (techradar.com)
• On realism and whether callers realize they’re speaking to AI: AI‑phone vendors highlight hyper‑realistic, human‑sounding voices as a key feature, and at least one high‑profile case (Phonely’s AI agents, deployed in real contact‑center environments and used to replace hundreds of human agents) reports accuracy above 99% and explicitly claims that customers “can’t tell they’re not human.” (venturebeat.com)
• Research and product releases focused on low‑latency LLM‑based voice agents for telecom and call centers further confirm that significant R&D and deployment are now aimed squarely at real‑time phone support, not just text chat. (arxiv.org)

Adoption is not universal and many centers still use humans or hybrid human+AI. But by late 2025, there is a clear, industry‑recognized wave of AI phone agents replacing or front‑lining IVR/call‑center interactions, and several deployments show voices realistic enough that many callers do not realize they are speaking to AI. Directionally and qualitatively, Sacks’ prediction has come true.