That makes sense and is a great suggestion. It makes sense that spellcasters should have at least one cantrip as a weapon set along with their melee and ranged weapons.
True, that's why cantrips have been made into caster's basic attacks in 5e in the first place... they even get their main attribute bonus on attack and damage rolls with spells for that reason. Physcial weapons shouldn't be caster's primary mode of attack.
That's why it especially problematic that - in addition to cantrips getting more damage dice with levels - Larian also gave those spells extra environmental effects.