Because Facebook is simple. Any one can update it, and it doesn't go down, and it doesn't cost anything.
I've many times seen web presences fail for small organizations, when the only person that understands the web set up leaves. With Facebook, that doesn't happen.
I'm sure there are services such as you describe, and probably many restaurants use them, and it's not obvious. But Facebook is the default.
No, because facebook is free and they are cozy with the mexican government and this allows them to operate in a country without net neutrality. Therefore facebook, whatsapp and instagram are included for free in most if not all cellphone plans and pay per month options.
I've seen that too. Or when the framework chosen goes away. If the person at a small restaurant or non profit who understood the page goes away you can at least find someone to come up to speed. But sometimes it relies on stuff that just isn't there anymore and you have to start over. I'm not in web dev, or whatever its called, but is there some technology in the space that is the equivalent ofba T-shirt and blue jeans, or a charcoal suit, that will be fine for a couple decades with only informational updates?
You have to constantly install updates for it to stay secure, then every second update your theme breaks, you find out it's not updated for the new version and have to redesign the whole page.
I've many times seen web presences fail for small organizations, when the only person that understands the web set up leaves. With Facebook, that doesn't happen.
I'm sure there are services such as you describe, and probably many restaurants use them, and it's not obvious. But Facebook is the default.