I think the main function of produce flame is to be an attack cantrip. The illumination is just a bit of flavor.
I don't disagree, but if that is the case why not just give them Flame Bolt? Every other cantrip attack with "Flavor" is functional.
Chill touch 1d8 necrotic, prevents regeneration
Ray of Frost 1d8 cold, reduces speed by 10
Thorn Whip 1d6 piercing, pulls target 10ft closer
Vicious Mockery 1d4 Psychic, Target has disadvantage on there next attack
Perhaps another option would be to just fix produce flame, something like:
Produce Flame
Conjuration cantrip
Casting Time: 1 Action
Range: Self
Components: V, S
Duration: 10 minutes
A flickering flame appears on your hand, the top of your staff, or end of your wand. The flame remains there for the duration and harms neither you nor your equipment. The flame sheds bright light in a 10-foot radius and dim light for an additional 10 feet. The spell ends if you dismiss it as an action or if you cast it again.
You can also attack with the flame. When you cast this spell, or as an action on a later turn, you can hurl part of the flame at a creature within 30 feet of you. Make a ranged spell attack. On a hit, the target takes 1d6 fire damage.
This spell’s damage increases by 1d6 when you reach 5th level (2d6), 11th level (3d6), and 17th level (4d6).
---I think this is enough to keep the Light/Flame Bolt as better with 2 cantrips but make it functional.