Don't they have ads on pay TV too? "Free plus ads" is not the norm. In some countries you pay tax for national TV and you still get ads. Sports matches are only available on paid services and they stick as much advertising in them as they possibly can.

They only show ads for other shows on their own service (at least in my region), and they're skippable, but I'm not defending it, it's still bad and serves no purpose for the customer.

What bothers me more with Prime is that when I finish watching the latest episode of something, as there is no next episode, it starts playing something entirely different I have no interest in watching, which then ends up on my "Continue watching" list.

It's like nobody has ever watched cable TV.