I echo what everyone else has said. Smart TV UIs are usually slow and have poor design. Apple TV is also regularly updated and maintained. I view built-in Smart TV features the same way I view Smart TV speakers. While it’s good enough, it won’t be as good as a dedicated soundbar.

If none of that is important to you, then no need to spend more money on another device. The built in stuff is good enough for some, if not, most.