>>52915647Since they changed it so that the whole team gets EXP from defeating Pokémon, the whole team also gets EVs, so you can EV train six times faster.
When Pokémon hold "Power" items, which can be bought for $10k each from the Delibird shops in SV, they will gain 8 EVs in a certain stat in addition to whatever EVs they would have gotten from the Pokémon.
For an ideal setup, you would look for an outbreak (or at least a consistent spawn) of a Pokémon that gives 2 EVs in the stat that all six Pokémon need (for Raids you almost always want to invest in HP, so you'd look for a Marill or Vaporeon). Have the Pokémon hold the Power items in the other stat they need (Bracer for Attack, Lens for Sp. Attack, etc.), so you max that out while slowly building up the common stat, and then switch them all over to the common stat to finish it off.
According to Bulbapedia, in Gen 6 you would also get EVs for catching Pokémon instead of defeating it (since that also gives EXP now), but that's no longer the case in Gen 9.
I've also seen people say that auto-battling doesn't give EVs, which sounds right but I haven't tested it myself.
