Are Kia low beams supposed to give off slightly less light than two barely lit tea candles going down the road at night, or is that normal?

I don't know if your headlights are the kind that run on high voltage transformers or if they have just standard 12-volt capsules if they are standard 12-volt capsules replace them because they're really worn out if they're the kind that run on high voltage your high voltage transformer is worn out

Go to a repair shop and have the light output measured.

No. Maybe new bulbs will help? Also clean the lenses with lens cleaner if necessary.