Robert Downey Jr's 4 syllables (2 + 2) hit the Hollywood sweet spot.
Robert's 2 beats vs. Downey Jr's 2 create a natural cinematic snap.
Robert Downey Jr's softer consonants cost it screen presence.
Robert Downey Jr misses the alliteration hook that makes names stick.
Robert (6 letters) and Downey Jr (8) are balanced in length — clean on any poster or marquee.
Robert Downey Jr has mostly familiar phonemes with a few tricky patterns.
Robert Downey Jr's open vowels roll off the tongue — warm and screen-ready.