They're entertainment, yes, but really not the same. I'll look for a specific game to play, I'll look for a specific movie to watch, and I won't play a game when I want to watch a movie.

No, they're not the same, but the amount of time people have for entertainment is generally fixed. In the old days, they spent it reading books or socializing or doing a hobby like playing music or painting. Then radios were invented and people spent some time doing that. Then movies were invented and people spent some of their time going to those. With each new type of entertainment, people spent less time per-capita on the previous forms of entertainment (generally; radio was probably a bit unique because it can be done simultaneously as other activities such as driving, but in the old days it was a family activity).

Video games are doing the same thing. You can't watch a movie (easily) if you're playing a video game.

Yes, and yet by the counts, Westerners watch more televised content than ever.

If anything the substitute has been TV. Gaming is big, sure, but that doesn't appear to crowd out time reserved for watching media. I expect that the marathoner gamer who plays for hours daily is a comparatively smaller demographic.