It might not be the only reason, but it's sure as hell a very big one when it comes to voice roles. Especially with a character like Doom they're going to want to find a person with a unique, recognizable voice, who people will hear in Marvel movie, and instantly know it's Doom. I refuse to believe that the uniquness of James Earl Jones voice was not the primary reason he was cast as the voice of Darth Vader, that's the kind of character where you want people know it's him the moment you hear his voice. And a version of Doom where his face is hidden, is going to need to have that same kind of voice, and Robert Downey Jr.'s voice isn't quite at that level.
A vocal performance is not just about timbre, and Downey can modulate his voice from role to role. In the
Sherlock Holmes films, he gave Holmes a more deep and booming voice than he gave Stark; to an extent, he was recognizably homaging Jeremy Brett's Holmes. I think a voice like that would be pretty good for Doom, though maybe that's because it reminds me of Simon Templeman's Doom voice in the '90s
Fantastic Four cartoon.
Inneson was in First Knight, the last three Star Wars sequels, Guardians of the Galaxy, and the first Kingsman.
IMDb and Wikipedia say he was only in
The Last Jedi, though he was also in the last three
Harry Potter films, so maybe that's what you're thinking of. Anyway, I don't recognize his character names in either of those or GotG, and I haven't seen the others.
But my point is that it doesn't matter, that actors are not cast solely on the basis of name recognition. Whether you've heard of someone and whether they're the best performer to portray a character are two completely unrelated questions.
Downey is a good actor, at times a great actor, but one of the greatest actors of our generation? You've obviously never seen Dolittle...
First off, nobody bats a thousand, so it's ridiculous and petty to cherrypick one bad example as an indictment of someone's entire career. Second, I said "great," not "greatest."
Honestly there's a big reason Marvel have paid him the earth to come back, and it isn't for him to disappear into an unrecognisable role.
You
assume that. As I said, it's foolish to think that audience recognition is the only thing filmmakers consider. Even aside from talent, this is hiring someone to do a
job, to work with the filmmakers day after day for several years, possibly a decade or more for a role like this. What the audience will see for 2-3 hours every couple of years is a minor consideration compared to what it would be like for the cast and crew to work with a person regularly for years on end.
That's why it's entirely common for directors and producers to keep hiring the same actors to play different roles, like Tim Burton and Johnny Depp, or Alfred Hitchcock and Jimmy Stewart, or Joe Dante and Robert Picardo, or James Gunn and his brother, or the makers of
Star Trek and Jeffrey Combs or Vaughn Armstrong. The actors they've worked well with before are known and trusted commodities, people that they know can not only give a good performance, but can be relied on to meet their professional obligations and are agreeable to work with personally. So it's natural that they'd want to work with them again. The only thing different about Marvel Studios is that all their movies are set in the same continuity. But that's a distinction that only matters to the audience. From the filmmakers' perspective, the continuity that matters is the real-life continuity of working together with someone for years and wanting to keep working with them. Maybe Feige just enjoyed working with Downey and wanted to get back together with his friend.
Ineson is perhaps best known for his role in Robert Eggers' The VVitch, and he's worked with Eggers twice more. A respected character actor he's known for a phenomenal voice, so much so that as often as I see him acting on TV, I hear him voicing adverts. Honestly I think his voice is the main reason the MCU have hired him for Galactus, and I think it's nonsense to imagine actors aren't hired, on occasion, for the timbre of their voice.
Again you misrepresent my words. Obviously timbre is important, but it's foolish to think it's the
exclusive consideration.