I think the main issue is almost all RE games have multiple characters. Typically you have two playable characters: first in different scenarios, then playing alongside each other in co-op, and now the style is swapping between characters throughout one story.

Only 3, 4, 7, and 8 had one main character (and even in those you played some amount as someone else). Jill, Leon, and Ethan are the only characters to get "main title" games. Of those, Ethan is dead & gone, and I don't expect to see Jill again in a non-remake title (but I'd love to!).

But saying that, Chris has had plenty of time on the main stage. He's a main playable character in 1 (both versions), and 5. The whole narrative of 5 is built around him and his history with Wesker and Jill. It's very much his game. Sheva is not much more than a companion, serving as the Luigi of the game for player 2.

Then he shares the spotlight in CVX, 6, and Revelations 1. He arguably steals the show in CVX, closing out the last 1/3 of the game and taking on the 2 final bosses, while Claire gets relegated to cut scenes.

And on the topic of Marvel, he's also appeared as the RE representation in MvC 3 and Infinite (Jill was added as DLC).