Built-in apps just suck, and the OS the TV runs only get updates for a couple of years. If the Apple TV goes away, I’d probably use my PS5 or Xbox for TV apps.
I agree that the Apple TV box offers a premium experience but I think fewer and fewer people will buy one unless Apple adds something unique. It doesn't help that you have to switch inputs, which creates friction. Two possibilities consist of pursuing console-level games or replacing the cable box/DVR.