what are the benefits of owning the device Apple TV

it's like an ipad that use your tv as display so you can get games and apps from it's app store and play the games on your tv and stream media from the various apps, and or airplay audio and video from mac computers and ios devices

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Apple TV 4K - Apple

Beyond the obvious "Apple TV feature list" and it just fitting into the Apple ecosystem and effortlessly providing you with a familiar interface to enjoy entertainment on a big screen?

A recent reason for me upgrading to the latest Apple TV 4k is because I absolutely loathe the "smart features" of modern TVs. I recently purchased a new LG C2 OLED - its a FANTASTIC screen with a quality you cannot fault - but the WebOS interface is seriously pathetic from a UI perspective and the application performance is not on par of running the same apps on the Apple TV - or even Android phones. Add to this the added requirement of subscribing to LG to "unlock" features that you already paid full price for is just rubbish - and if their recent press is correct, LG is doubling down on offering more subscription only based services on their devices.

I have already bought into Apple so its logical to take the Apple route for the TV too - especially when its actually pretty **** good.

Also see this comparison for the Apple TV app vs. the Apple TV box:

Apple TV app vs. Apple TV box - Apple Community