For LA, love the cap hit, but not the term. He still had 4 RFA years left, right? So this only buys 1 UFA year? Not quite as bad as walking him straight to UFA, but close. If I'm the Kings I would've strongly preferred either a true bridge deal (2-3 years, where he's still an RFA at the end), or a 7-8 year deal.
With that being said, the player-friendly term is certainly why Byfield was willing to take such a team-friendly cap hit, can't really have it both ways. At least they didn't do what Dubas did with the original Matthews/Marner RFA deals, where he gave player-friendly term AND cap (and I say that as a Leafs fan). This is a very nice deal for the Kings for the next 5 years, and if they see that as their prime contention window, then it being a worse deal for the future is maybe a fine tradeoff for them.