Not really, it replaces the attack stat with the spellcasting stat, kind of like shillelagh but only for a single attack, and then stacks some radiant damage on it at higher levels (+1d6 from level 5 then cantrip leveling). It can also replace the damage type with radiant. Useful for any weapon-using caster class that doesn't get multiattack:

• Clerics would be a great target audience for this, except it's not on their spell list. *sigh* Magic Initiate (Druid) it is.
• It could be useful for non-hexblade warlocks too.
• It's a great damaging cantrip for bards who severely lack those.
• It's good for even a sorcerer or a wizard, it turns the light crossbow into a long-range radiant-damage cantrip.
• Arcane tricksters: could be useful depending on the build, probably pairs really well with a headband of intellect. (Edit: Or an extremely INT-focused Arcane Trickster with a 2-level wizard dip for the bladesong.)
• Eldritch knights: really useful at levels 1-4 if you're running into some monster that resists or is straight-up immune to nonmagical damage. Markedly decreases in usefulness once you get multiattack and/or a magic weapon.
• Probably good for artillerist artificers (they are not in the UA so it's unknown whether they'll get this cantrip), might be good for alchemists, OK for battlesmiths until they get multiattack, and redundant for armorers.

How I'd improve it further:

1. Make its casting time 1 attack and limit it to once per turn in the fluff. That way it stays useful for eldritch knights, ~~bladesingers~~ (scratch that, bladesingers can cast this in place of an attack already), valor and swords bards, and the two multiattacking artificers (less so for the armorers, but even then, it gets them a good ranged attack in a guardian suit or a good melee attack in the infiltrator).
2. Add it to the cleric spell list. They are the full casters most likely to go into melee even without the multiattack.