You can upcast it for more damage. It gets 1d8 every 2 levels of upcast. But there are much better uses of your higher spellslots, like Spirit Guardians. As for missing, the attack roll is based on your spellcasting modifier. At level 10, you should have 20 points in Wisdom, which would give a +5 bonus to its attack rolls.

With some exceptions, the only things in dnd (5e) that typically scale with character level are cantrips, class features, and anything that uses your attribute modifers. For spells, you generally either upcast for some improvement, or (more often) use more powerful, higher level spells. But lower level spells can still be useful in their own right, especially if you play the game as intended and don't long rest excessively, since then you need to manage your resources carefully and higher level spells slots are in shorter supply than lower level ones.