One of my biggest issues about Shadow is that he has too much screentime that prevent other characters on having the spotlight. While I understand some spotlight like Sonic Generation and the movie because it is a way to add lore on Shadow and also let new audience to see Shadow in cinematic uniserve, but he doesn't need to hog the spotlight. Like wouldn't it make sense for Jet to be the main focus competitor on the Crossworld comic over Shadow, he has racing experience than Shadow. I heard that the Lunar arc wasn't supposed to include Shadow and Rouge and just added it becaude of the movie promotion which makes one of the reasons why this arc falls flat besides the arc being too short and how written Lunar was with the family issue (which you can compare to Shadow's appearance in 80 to be well-written even having Rouge a spotlight). Even the animation promotion on Crossworld is Shadow and wouldn't it make sense for Babylon Rouges to be in the spotlight.
I get this is promotion for everyone to buy the games and other medias, but this kind of spotlight prevents other to have their own spotlight even having much appearance to future games.
AGREE AGREE AGREE. I don't have much to add since you've already described it perfectly... And oh, if the Lunar and Soleil thing is right I'll be so mad. MAN THE ARC WAS 3 ISSUES LONG AND HALF OF IT IT WAS SHADOW. Lunar and Soleil are really cool characters and if we don't get more of those two because Shadow and Rouge hogged all the attention I might become a Shadow hater (I'm joking, but seriously, first plural representation in Sonic, one that seems pretty positive, but we get barely ANYTHING because Shadow was there and the family conflict got resolved in 5 lines of dialog, what a joke)
At this point Shadow is the money maker of the franchise that they'll just slap in anything without thought. It's sad because he's a cool character when he's there for a reason...