I think HHH can still bring it in the ring, but he's way too overexposed. It seems like every RAW starts with a 20 minute HHH promo and ends with HHH in the main event, and in the middle everyone talks about what HHH is doing or what his plan will be.
The casual fans are bored shitless with HHH, and WWE is going to embarrassing lengths to hide it. Why should they be emotionally invested in anyone on RAW since the moment they become popular, they're immediately booked to face (and get dominated by) HHH for no other reason than to prove he's the dominant alpha male.
Look at Hurricane, Rock gave him a rub and despite the fact that no one expected Helms to main event because of it, to this day when HHH wants to make the point that he's angry we get him beating up on Hurricane. RVD caught on with the crowd, and BAMMO he's booked to be clearly inferior to HHH.
What really becomes annoying, is when the heat starts to rise on him, he'll do some safe jobs he can point to later, "see, I'm a company man, I laid down for X". Of course whoever he jobs to usually ends up returning the favor in triplicate.
It becomes a self-fulfilling circle jerk of a prophecy. HHH can honestly say no one else on RAW can carry the ball, but the main reason he's seen as the only real main eventer is because he's booked himself to thoroughly dominate everyone he faces.
HHH-Batista III is a prime example. Kayfabe-wise there's no way HHH deserves a title shot. He lost twice already, yet he gets to make the demand to the champion that not only does he get another match, he gets to name the stip too. Way to completely remove your champion's balls. Batista should have just told H to go fuck himself and make him earn a title shot like anyone else. Instead, we get the big, bad Animal allowing his enemy to set the terms for his title defenses.