I mean, a single Wizard can cast Dancing Lights to illuminate an area your Fighter can't see well; can cast Fairie Fire to give all your party Advantage on attacks; can cast Hold Person to lock an enemy down; can cast Sleep to guaranteed a party member a melee Critical Hit.
A Fighter can Threaten an enemy to allow a Rogue to make a Sneak Attack;
an Arcane Trickster can cast Magic Missile to do guaranteed damage to a target unlocking a Ranger's Colossus Breaker ability;
A Cleric can Turn Undead to reduce the number of enemies your Fighter has to defend against at once;
A Druid can cast Make Water over a bunch of enemies so a Warlock casting Witch Bolt hits his target and also electrifies the water surface the others are now standing in.
There a lots of possible interactions and synergies,, but they are somewhat different and less obvious to many modern games. Another issue is that the Advantage/Disadvantage mechanic has been simplified to the point that its so easy to get anyway, any intended DnD method is pointless.
Last edited by Elessaria666; 26/02/21 06:52 PM.