I began my career building IVR systems in the early 2000s (Nuance, etc). In college I worked at my university's speech recognition lab. I remember an uneasy feeling while building and testing my first speech application. I thought: "This is a statistical algorithm with nothing else behind it. It's just a good guesser over a very limited domain of 'knowledge'."

At the time the tech industry was hailing speech recognition as the next big thing. There was a lot of investment in speech: BeVocal, TellMe, Nuance, SpeechWorks, AT&T, L&H, etc. Replace your call center workers with automated systems, use voiceprints to secure sensitive transactions, etc. Amazing AI would effect cost savings and make your business efficient! Sound familiar?

Very few users actually liked these systems over the previous versions that just used the phone keypad. Poor recognition accuracy really pisses users off. And most of the time the recognition errors aren't the user's fault. Ever try to recognize speech on a cellular channel using an acoustic model trained on a landline channel? Crap! This was certainly a problem during the early 2000s because of the emerging mobile phone market.

The UIs (or VUIs as they were called) were awful since they mostly replicated the touchtone versions but added "you can say 'accounts' to...". They continue to be awful because, while speech recognition had gotten a lot of funding (DARPA, etc) in the past, the UI aspects were pretty much ignored and underfunded. People interact very differently when speech is used as the medium. The interaction automatically becomes social. Social interactions with machines are decently well studied (Cliff Nass for one), but the very nuanced aspects are difficult to bake into an IVR system, especially under pressure to deliver on a deadline. The experience feels unnatural very quickly and users either run for the door or starts mashing the keypad.

Ultimately the web killed off industry interest in IVR systems. Want to know your account balance? Log in to a web site and it's right there. No need to dial in your account number, verification and run a gauntlet through a phone menu.

Fast-forward to today and chatbots are the new IVR systems, but without the speech-to-text portion. The speech-to-text portion is the easiest part by far in those types of systems. There's still the need for a parser (shallow or otherwise), a way to pair up queries with responses/actions, the ability to track a dialogue and its context, and most importantly, a "natural" feel to the interaction.

Chatting/texting and speaking are serial in nature; very slow and inefficient. A well-indexed FAQ or an intuitive, well-designed GUI is more useful than a chatbot. The former helps in shortening search time and the later helps at streamlining transactions. Information search and transacting comprise the majority of actions that users perform when they visit a site/system/application. When you talk to a human agent for these two types of actions, guess what they're using to assist you? The same interface you'd use if you served yourself. They just know it better.

As an aside, the only noticeable/innovative use of chatbots I've seen in the past 10 years is on porn sites. I really took notice of the messages in the chat window when it started nagging me for ignore it. I wouldn't be surprised this round of chatbots were inspired by that.