Let’s not call it digital, because both are digital. Let me refer one to disk and the other to Demond. 😁 Chances are you won’t notice it on the picture. But audio you might have more dynamics. But I doubt you will watch both on demand and a disc version side by side to notice the difference.
I went completely away from physical media for movies because of the minimalist standpoint. And rocking the on demand media over Dolby Atmos surround sound and Dolby Vision on an OLED directly over the TV (since Apple TV is causing problems since the latest update. Different story) and as long as the movie is good I am immersed in the movie. 😊
More importantly, ask yourself when making popcorn 🍿 with butter and salt or sugar? 😁👍
I would see it more on the content side of things. Is there anything you like to access now that the Apple TV offers? Then yeah it’s worth it. Also check if your TV has Apple TV already.