Why damage cantrips? Can't use them with extra attack feature. GFB with level 20 oath of ancients is cool, but I'm never getting that far with this char. So... why?
Not from the Wizard list as a Cha-Based Caster who's already MAD you can't.If you're a class that gets multiple attacks, then yeah I don't see much point in getting the SCAG Cantrips. One of the standard Ranged Damage Cantrips would be the only one I would recommend in that case since it scales with Character Level and you can use it as your "go-to" ranged attack.
As a slight twist on the Warlock, path of the Tome and the Book of Ancient Secrets invocation can give you Find Familiar via ritual casting, and much more utility casting than the feat because you can do rituals from every class. Augury, Commune, Divination, Forbearance, Meld into Stone, Speak with Animals, Water Walk - these are a couple of the ritual spells not on the wizard list.
But tome would also allow you to pick up Shillelagh and let you base your melee attacks off of CHR with a limited selection of weapons.
Yes, I might multiclass into Warlock, but definitely not until Paladin 5. The problem is that Paladin 6 and 7 also give amazing features. Then Paladin 8 gives an ASI, and 9 gives 4rd level spells Paladin 10 gives another great aura, and 11 gives Improved Divine Smite.
Basically, every level of Paladin is awesome. MC into warlock would be cool for the short-rest spells slots, invocations, and pact boons... but...