Probably because Amazon Prime would rather be straight forward with their customers and ensure they get their customers' questions answered to the absolute best of their ability to avoid any sort of confusion using chatbots, and/or a most likely VERY busy email address that very few people probably have access to via their site. I have actually never heard nor seen anybody complain about authenticity, or live chat, or phone call where you can get your question or questions answered much faster, vs. waiting for and possibly potentially even missing their reply email because you would have to be sitting around waiting on an email reply, for however long that'd take. Trust me, if you really want your question(s) answered, this would by far be the best option. There is even an app and/or extension you can use called "Amazon Assistant" That feature normally gets any and all issues solved, and FAST! I hope this helps! :)

If you only knew the scope of how BIG Amazon really is, you'd understand the need for vetting questions/issues. It's no different than other large corporations. If they provided you with a staff that was dedicated to answering questions via emails, you can count on their operating costs to soar, along with their retail pricing.

There is an Amazon phone number that I've used a number of times. They are very helpful.
I wouldn't "chat" because it's a pain. You would actually think an email would be easiest but it's Amazon. Imagine the number of emails they get? They must be inundated because it's one of the largest companies in the world.
You want a live voice. I always call and calling them has always been pleasant, they just make looking for the number challenging.
It's 1-888-280-4331

Because it discourages you from actually calling to complain.