I'm not seeing how this current Lakers roster is vastly better than the Cavs. The Cavs had more veteran players in must-win-now mode while the Lakers look like a team that's rebuilding with young guys like Lonzo, Kuzma, Ingram, etc. Throwing LeBron on a team that's gonna take at least 1-2 years to develop seems awkward. I think the Lakers' team is better, but not worth leaving $50m on the table for. Maybe Magic told LeBron it's going to be a two-year process and there would be more acquisitions next year.
They also need shooters badly, they need someone like Korver or Reddick who can just spot-up in a corner and make shots. I think LeBron will probably like Walton's offense where he can play off the ball a lot more, but if they're not adding another star player then I don't see then coming close to threatening the Warriors. I think it's possible that the Rockets may even be able to compete with them for #2 in the West.