Obviously, a TV is much better when watching with multiple people. But even when alone, I much prefer watching on a nice large OLED TV at a very comfortable focal distance with a nice immersive speaker setup while sitting on my comfy couch, unhindered with holding or propping up a display relatively close to my face. I do watch plenty of content on my other devices, but only because of necessity/convenience when I'm not able to be in front of my TV. Anything cinematic that I care about though I will save for watching on my TV (preferably at night to simulate the movie theater experience). You can never beat or fully replace a dedicated immersive experience with one that has to fulfill other functions such as being mobile. The only exception might be the Vision Pro because of what it uniquely offers, but it has obvious trade offs of its own.
But of course, a nice iPad display is probably better than a mediocre TV, so it really does depend on your setup. But in ideal situations, the TV is more ideal in my opinion.