You don't, save your money.
It is enormously overpriced and most Smart TVs/Rokus/Fire TVs are good enough these days.
Meh. "Good enough" is all a bit subjective isn't it?
I'm not saying you are wrong, for you, this might very well be an accurate statement. That doesn't mean it is for others though. Does all the streamers play video? Yes.
Things I like about my Apple TV that my LG G1 doesn't give me? Like with most thing "apple", the integration with the ecosystem is a win here.
- Photos integration. It's fun to share photos "memories" on the big screen when family, is over. Heck, my and the missus sometimes does just between
- As an Apple Watch user, that regularly use Apple Fitness from time to time. TV + Apple Fitness isn't a bad combo. We are both regular gym goers (4 days of resistance training a week), and yes, the apple workouts aren't its not terribly intense, but, it helps with supplementing my exercise minutes on offdays.
- Apple Home integration is neat (fact it also doubles as a home hub now is a plus)
- Apple Arcade works well when the screaming nieces are visiting and needs to be pacified
- Apple Music works beautifully with my Dolby Atmos setup via Apple TV.
- Subjectively, the video quality is great. I feel iTunes content is second to none on Apple TV. And generally, whilst its not something I did any deep research into, it just felt like its doing a better job matching content to my TV (frame rates, HDR format etc) than the android TV box I used to own (my only point of reference is a Nvidia shield).
- The teleconfering with family feature, via iPhone continuity, with centerstage and such, is also a welcome new feature (once it lands).
All in all, I feel the Apple TV, for me, offers far more than the alternative. Granted, like with any other apple device, its value is proportional to how deep into the ecosystem you have gone. But I'm cool with that.
Sure, I suppose I could achieve most of the above with AirPlay via my phone. But, personally, I find the experience, a bit more clumsy. I prefer just picking up the remote.
And finally, it's dirt cheap. And you rarely need to upgrade. For me, I cant see any reason why not to have one.