Sure, they were really good to begin with, but why do people still like them? They are literally the same every single time.
Slow start. Cena hits 5 Knuckle Shuffle after opponent counters it the first time. Both wrestlers hit their finisher and the other kicks out. Then a 5-10 minute sequence of both guys hitting all their signature moves to false finishes. Then both guys hit their finisher again near the end, with the person hitting theirs second winning the match.
There is no psychology at all to his matches. It was cool to start in his US Open Challenges but I don't know what about it still gets people so engaged. You're just watching the same match over and over again.
And this isn't a Cena bash thread. I like the direction his character has taken, even if it has been minor. And I don't think it is his fault his matches are this way. I just think they kind of suck, especially compared to the more old-school, psychology based approach NXT takes.