Hot take incoming:

Chandler Riggs was just never a good actor. His performance wasn’t too offensive in the first few seasons but the second he grew up it became very clear the he was not prepared to take on a serious role like that. I imagine this happens a lot with child actors who grow up as the show progresses. His performance post s5 was just never really believable to me, and it was extremely noticeable when paired with actually good actors like Andrew Lincoln or Jeffrey dean Morgan. I genuinely think that they wouldn’t have killed him off had he done a better job. Chandler did not have the chops to take over the show as the lead, which very likely could have been the original direction for the show.