Wiggins will almost certainly play longer than Love. I think everyone can agree on that.
Wiggins would almost certainly play better next to LeBron. I think everyone can agree on that too.
But the only way that extends a championship window is if Wiggins is great. Right now Wiggins gives you the rebounding of Kyle Korver, the jump shooting of Russell Westbrook, and the passing of Al-Farouq Aminu. He could be prime Dennis Rodman defensively and that still wouldn’t even be a good player, and this is reflected in his composite stats: PER 12 lower than his USG (league average is 5 lower), WS/48 .07 (league average is .10), WP/48 .09 (same), RPM -1 (not sure what league average is there but I would guess 0).
There have been guys to put up stats as bad as this and later turn into superstars, but it’s very rare for an eventual superstar to still be this mediocre in year three; the only one I can think of is Scottie Pippen, whereas I can find hundreds of guys who were this mediocre and stayed this mediocre.
I don’t dispute that many people have told you they’d rather have Wiggins, but if there’s no objective evidence to demonstrate he’d make the Cavs better, perhaps there are other explanations for them saying so.