Some of us have been watching football since the mid 90s and have seen hundreds of hours of Rooney play as well as being exposed to the various debates across time about his potential, his performances, his impact on the team, his best position and so on, alongside with the various tabloid stories about his lifestyle. That doesn't automatically make people experts, and produces all kinds of diverging opinions but it does at least give a base sense of how good he was, but also what some of his flaws were along with his unrealized potential . There's a good case, if not an unequivocal one, that Kane at his peak is just a more creative player in terms of linking things together in the final third as well as regularly starting moves off.
I'm not saying he will (returning to PL for the Shearer record might get in the way of this, for a start); I'm saying in principle he's arguably better suited to this than Rooney ended up being once he got into his 30s. The arguments were that Rooney would essentially go from Scholes CF/Second ST of 95 (but at higher level) to late-career Scholes (sitting deep and dictating play, as well as moving forward when needs be, rather than the more dynamic peak-period Scholes CM role which Rooney's decreasing mobility would stop him from potentially. There was a bit of that towards the end of his career with Everton and, mainly Derby, but we didn't really see it. Prior to then, late in his United career we saw something closer to Rooney trying to play the 'peak' Scholes role, albeit in slightly different tactical set-up, but I don't think he played it consistently, even in terms of controlling tempo and short-passing, breaking the press or finding overlapping full-backs and all the rest. Some of that was just down to playing in weaker sides by that point, of course...