Why John Cena is not impressive as a maturing pro-wrestler?

I was just seeing the latest Summerslam match which had Roman Reigns compete with John Cena. Though there was nothing too impressive or outright dislikeable about the match, I must say that Cena is not balancing the maturing act too well. Many former and recent superstars from the WWE have run the seasoned course a lot better. However, John Cena seems to be struggling. His 16-time World Champion credentials stand and he still has the physical strength, but largely, he seems a bit lost, and this is why:

1. The boyhood charm is not working anymore

When John Cena started, one thing that caught everybody's attention was his boyish, cute looks. He seemed a bit undercooked and too much of a collegiate wrestler for many, rather than being a serious pro-wrestling contender. However, as things progressed, the same looks became a bit of a signature for Cena. Even when he completed a decade in the industry, the clean-shaven face, and the short, cropped hair, looked the part. Cena seemed blessed with sort of an anti-aging gene - this is what many people had to say and yes, his chiseled physique only strengthened this image. However, now that Cena is clearly a senior in the industry, the hair is thinning, and the boyish charm is not radiating. The hip-hop mad looks are not delivering. In fact, he seems to be oscillating in a state of confused identities. I compare him to Michael J Fox and Tom Cruise - two more faces that refused to age for the longest time but when aging did start showing up, it just did not blend into their persona. Cena seems to be going through something similar. The white sneakers and the Bermuda-like ring attire seem to contradict that along with Triple H, he is perhaps the most experienced ex-champion right now.