It's tough to evaluate the potential of this team since the West is so wide open where a 50-55 win team will probably be enough to reach the Finals, so I can't say that this move doesn't make the Lakers into a contender. They are obviously are just by having Lebron and Davis, but so are all the other top 4 West teams aside from a depleted Golden State. However, if Golden State were still 100 percent plus Durant, the Lakers as-is wouldn't have a chance. Nor do I think this Lakers as-is team has a chance against a potential Raptors (provided Kawhi stays), Bucks, or Sixers team.
This isn't a big man league anymore. With how statistically dominant Davis was per raw stats, he "only" ranked 7th in RPM. If Lebron is still in retirement mode going into next season, I don't think the Lakers have a better chance than Denver, Houston, Portland of reaching the Finals. West playoffs will be a crapshoot. You need efficient volume 3 point shooting to win les. Davis doesn't help with that.
Lakers need to add at least two efficient volume 3 ball shooters. Kemba is probably their target now. Then you add some VanVleet like microwave player, and their only compe ion in the league will be the Kiwi Raptors or a Bucks team that has reach the next level.