When factoring in player for player trades, role and position are almost as meaningful as talent-based attributes. Winger is the lowest value role/position while 1C is the highest. If you trade a 1RW, for a C, you're looking at trading for a player that's a tier lower in talent. Byfield in my opinion, looking at how everyone (not just Kings fans) rate him, is at least equal tier to Kakko. But he is a 1C. You're looking at getting like a Perfetti or Rossi-level 1C prospect/young player. It's the same reason why Kakko was available to draft at #2...because the 1C Hughes was picked first.
And I don't think LA is interested in trading down Byfield for Kakko +. On the other hand, we have literally a smorgasbord of other (non-Vilardi) young centers both in the NHL and lesser league center prospects we could discuss. Maybe you get a future 1bC/2C and a future 3/4C to go with Chytil to sort out your entire center corps. (If you say no to Kakko for our other centers, now you know how we feel about trading Byfield for Kakko +.)