You make a good point, @Gins. I think the reason for people to discuss the de-aged Ford instead of the younger Indy is because that, and the AI they used to pull it off, is a hot-topic at the moment. Plus, since it’s conception it has mainly been used to show off bells and whistles instead of adding to a story.
Then there’s the fact that casting a younger actor for a teen version of a character has been done countless times, and is (maybe therefore) easier to swallow for an audience. The fact that this steers away from the uncanny valley effect (because we as an audience all see and know it’s a different actor) makes it easier to divulge in the suspension of disbelief, whereas with de-aging, it looks almost real but not quite, so we subconciously go looking for mistakes as to prove we’re being tricked.
I was sceptical at first, because the feel of the Indy films, to me, relies very much on practical effects and the grit that comes with filming that way. A CGI de-aged Ford to me sounded like everything it shouldn’t be.
However, I stand corrected. In the light of the story ánd the fact that this is the last Indy movie, I think the prologue scenes work very well. They not only set up the McGuffin and the bad guy, but also show us how far Indy (and we as an audience) have come since the character’s heydays. The de-aging is far from perfect, but I think It’ll become less distracting with multiple views.