> Or a phone number that you can actually call

Of course, but I skipped this because I had tried to stay in scope of a text chatting.

Personally, I'd love to see more businesses accepting texts (SMS/Signal/Matrix 3PIDs/WhatsApp/Telegram/whatever works for them - just clearly indicating that they do). I'm an US resident but not a native English speaker - and while I've chatted online a lot, I have relatively limited experience talking to other people. So I have some difficulty talking to people, especially if my and their accents make conversation... less smooth than we both would prefer. Or at least I feel some non-negligible amounts of uneasiness before having to make an actual call. It's not too bad and I'm trying to improve as much as I can, but for some important conversations I'd rather use more reliable methods if those are available.

And to extend on this example, due to family matters I'm currently overseas in Mexico - and I only know very basic Spanish that is nowhere sufficient for any intelligible conversation beyond ordering food or asking for directions. Thankfully, almost every business seem to have a WhatsApp number so with a help of translation software I was able to do quite a bunch of non-trivial requests.

And while my case is maybe not that important (except for me), there are always folks with genuine speech and/or hearing disabilities who could be unable to use voice communication channels at all.

Oh, and texts allow asynchronous communications. I love that I can text my dentist office and schedule an appointment. I don't expect them to reply immediately (they won't if I text off-hours), but I know that they would receive my message and respond when they have a moment. Which is all I need, and my phone will notify me when they reply back.