Today in my personal theatre of ye olde me yelling at clouds:
I enter a shoe shop. Said shoe shop also has a website which lacks an option of checking availability of shoes in their physical shops. Imagine: a huge empty space with minimalistic cushions, lots of touch screen monitors/big tablets, and in the background, behind a strange metal contraption, a bunch of shoe boxes.
One of the sales people approaches and asks if I need help. I don't, but sure, tap the screen for me, why not, you're getting paid for that. In the meantime, I mention the site doesn't let people check the shoe availability. To which the sales person helpfully answers:
I'd have much rather preferred to explode, but I wouldn't take out my rage on a shop employee who's not responsible for website maintenance. And so I shall explode here instead.
If it's possible to look up product availability in one access channel, it means the database accepts such a query and returns a result. That means it's a simple matter of adding a button to the website with an API call that would run the same query and return the same result.
Not adding it to the website has been someone's conscious choice.
If something is possible in one access channel, it should possible in all access channels. Simple as that. I want a fully functional website, for fuck's sake.