＞It sounds like you're using the term solely to mean the highest heights of formalism, but I don't know where you're getting that usage.

The keigo you refer to is the easiest keigo to learn, and much of it is learned as a beginning learner as memorized words and phrases.

In the context of the person I originally replied to, this type of content is either trivially easy to study/learn or not worth learning (e.g., most learners don’t really need to know that おはようございます is a highly stylized form of はやい — the memorized phrase and others like it are more than adequate until one is an advanced learner).

The keigo that would warrant using an AI speaking partner would, imho, lean towards the much more complicated aspects of keigo.

Note that I have actually referred this tool to folks who do training in keigo (and other language things). I’m not sure how the tool will do or what type of prompts need to be used to get the right type of engagement, but I think that there is potential on this front for advanced learners. For lower level learners, this tool is massive overkill.

Edit:

Note that most English-language web pages about keigo cover the simplest (and least interesting, imho) parts of keigo. Part of this is due to SEO, but part of it is probably due to ignorance about the topic.

For anyone interested, and if their Japanese is good enough, just search Amazon Japan for books on keigo. The topic is quite deep and can be incredibly fascinating. The content covered on English web pages just scratches the surface of the scope of keigo.

As a linguistic category it includes teineigo and set phrases, but when a JP learner says keigo they probably mean the stuff introduced the "keigo" chapters of JP textbooks, which starts with おっしゃる, 下さる, いただく, お～になる and so on. And again, those are everyday usages that are perfectly reasonable for even an intermediate learner to want to practice (and the person you replied to may be beyond intermediate). Sure there's also lots of other keigo that most learners would rarely encounter, but that's no reason to jump all over someone who says they want to practice it - you wouldn't tell someone not to bother with kanji just because there are characters they'll never need.

> … which starts with おっしゃる, 下さる, いただく, お～になる and so on. And again, those are everyday usages that are perfectly reasonable for even an intermediate learner to want to practice

Serious question…

Unless this “intermediate learner” works in a Japanese-language position (like a 会社員), is a diplomat, or is involved in a traditional art (or these types of relatively rare categories), in what context would they ever produce utterances using any of these words appropriately and naturally?

This is just not the type of language that intermediate learners need to produce very often. When they do, their organization will most likely train them beforehand, use an interpreter, or just not care.

I lived in Japan 8 years, and I worked in a Japanese-language environment. I’m pretty sure the times I had the opportunity to use any of the words you listed appropriately could probably be counted on my fingers and maybe extending to my toes.

Granted, I was not in a position of power (those folks used keigo all the time), and I was not directly involved in any highish stakes negotiations or business transactions (e.g., didn’t buy a house) but still…

> in what context would they ever produce utterances using any of these words appropriately and naturally?

Part-time job? Friends or in-laws they'd like to impress? Studying for JLPT? Just wanting to be able to speak everyday Japanese as it's spoken?

Respectfully, I really think you have a distorted sense of this due to whatever your background is. Per a quick google, some of the terms I listed earlier show up in JLPT from level 3. I'm no expert but I don't think N3 is considered high-level diplomacy territory. If you got by here without using such terms that's fine, but it's no argument against studying them - lots of people get by without learning kanji, etc.