This explains the decision pretty much. If the game had server-sided attacks, you would have higher ping and slightly less bad hit detection, but because of ping there would still be some moments where “i hit him but it didn’t deal damage” or “i got hit but didnt take damage” would happen. So client side skills are ultimately better.
I don’t know where this whole cult of “client side spells bad!” started but yall are some clowns. It would have pretty much the same issues except everyone has higher ping, its not a solution. Every online game with pve/pvp has an issue with hit detection regarding ping, its just some have it less common than others. Even in WoM, its not a very common issue (or maybe it is and I’m thinking about AO idk I forget if its worse in WoM or not)
EDIT: also I forgot to mention client side attacks are more exploitable which is a downside, but theres some pretty easy fixes to this that are already in WoM + its easy to catch and ban people that exploit it. So it doesn’t really matter.