you've got a c9, so 4 years old, LG has a habit of updating the OS every few years, and not allowing the older models to do that update. Which means updates for the apps from various services become fewer and further between. since the developers won't do as many updates for a "retired" OS.
Every appleTV that supports tvOS is still able to upgrade to the current OS, even the aTV4 (now aTV-HD) which came out 8 years ago (and was discontinued last year). Developers can write one version of an app that will run on every one of those devices. There are a few features that require newer hardware (like continuity camera, VP9 codec)
siri voice search and dictation is nice, as well as being able to use your phone's keyboard to type.
The TV app is nice, it will consolidate most major streaming services in one place. (notable exceptions are Netflix and Plex). when you search a show, it will show you all of the apps where you can stream with a subscription or buy. Then once you watch something, it gets added to "up next" (you can manually add/remove too), then as new episodes are released they show up there, so you don't have to check multiple apps to see what new episodes you have to watch. And you'll also get notifications on your phone if you want when a new episode drops.
To avoid confusion...
AppleTV : a streaming box (piece of hardware)
AppleTV+ : a streaming service with lots of fairly good original content.
TV app : an app made by apple, you watch aTV+ content here, as well as the "consolidation" mentioned above.
Shows from other services can be found in the TV app no matter if you have a subscription to that service or not. When you select something to watch, the TV app will launch the appropriate other app. You need a subscription to watch things on the other services though.
Apple usually gives away a few months of free appleTV+ with purchase of the box, that only gives you access to their streaming service. The TV app works with other services no matter if you have an aTV+ subscription or not.
if you decide to get into home automation, the newer aTVs have thread built in. Thread is a new kind of wireless radio, Think of it as an alternative to bluetooth or wifi. Thread is designed for having large numbers of things that don't need much bandwidth. All you need is a newer appleTV (or HomePod) and a thread enabled device (like a light switch, smart outlet, or various sensors). Scan the code on the device with your phone, and you're good to go, no extra hub, or adding to your wifi needed.
Having a home hub (appleTV or homepod) will also allow you to control and monitor all of your smart home devices when you're away from home.
I trust Apple over LG for privacy any day.
My LG is blocked from the internet.
In order to use any app on the LG you have to agree to let LG monitor your "viewing information", and report back what you're watching. Even if you're watching something from your cable box, the AI in the TV will analyze the image, and report back to LG. Not sure how detailed it is, if it's "sports" "football" or " team vs team" but still very invasive especially on a premium set.
