Apple TV kind of confuses me. Is it that much better than just using the Apple TV app on an OLED LG tv?
The confusion ties in heavily to Apple's decision to call their device "Apple TV", their app "TV" (or "Apple TV"), and their streaming service "Apple TV+".
Their
app can stream their
streaming service, along with any movies or tv shows purchased from Apple (on iOS devices, the app can also download these for offline use, IIRC).
If you have the Apple TV
app on a smart TV, it's basically that same app, for streaming things rented/subscribed/bought from Apple.
The Apple TV
device, can run a large collection of tvOS apps - not just the Apple TV
app - tons of streaming apps and games and such. Many people think the Apple TV app on a smart TV is like a virtual Apple TV device - it's not that at all.
I've got an LG C1. I don't use the TV's built-in apps
at all. I use an Apple TV instead. It offers me a very
straightforward and very
responsive interface that has remained the same over the last 3 TVs, rather than having to adapt to the idiosyncrasies of each TV manufacturer's interface. And it has apps for pretty much every streaming service ever (it's very much in the services' best interests to keep their apps up to date on the Apple TV, because, just like with iPhones, they find the owners of Apple devices tend to be especially willing to spend money on software/services). So it's easy to run Netflix, Apple TV (the app), HBO, Disney+, Amazon Prime, Hulu, PBS, Peacock, etc., all on the same device (and all from the same overall UI regardless of what TV you're using). And if you should buy any apps (a game or something), they'll move over nicely to your next TV just by plugging the same Apple TV into that (and if you should upgrade to a newer Apple TV device, all the apps and settings and such migrate over to that too).
As well, Apple has a pretty straightforward funding model - you pay them a bunch of money upfront, and they sell you a very well made "premium" product. By comparison, a lot of TV manufacturers (LG not quite so much) compete heavily on price, and look for other ways to increase their income - one of those is ads in the interface (some more subtle, some more blatant), and another is collecting data on you to either share with (sell to) interested parties, or use to make you more lucrative to advertisers (either "we can show your commercial to people who like program X and movie Y", or "here's things we can tell you about the people living at this address"). By contrast, Apple makes privacy a major selling point to end users, and if they got caught doing that same kind of thing they'd take a major hit to their bottom line, so I'm persuaded that they'll continue this pattern of not trying to profit off my data.
FWIW, the only time I ever touch my LG remote is if I want to change something in the TV's settings, or on the rare occasions that I watch live over-the-air TV (lately that's basically just the Super Bowl and SNL). Other than that, I use the Apple TV remote for waking the home theater up, watching whatever, and putting it back to sleep. I also have a PS5, and a third party (PDP) PlayStation remote - I use that sometimes to control the volume when gaming, or to switch inputs on the odd occasions when the LG gets confused about which input I'm trying to watch (like if I bump the Apple TV's remote, waking up the Apple TV, and the LG switches to that input while I'm in the middle of a game). I find the LG remote to be adequate, but inferior to the Apple TV's remote - the LG is festooned with buttons I don't need that I have to reach over to get to the ones I want, while the Apple TV remote has just what I need, and I can navigate the buttons easily without looking. And the LG's gyroscopic "mouse like" control is cute, but is frankly a pain to use.