Is soreness a good sign that a workout worked?

No, and treating it as a scorecard leads people to train badly. Delayed onset muscle soreness mainly reflects novelty and eccentric loading, which is why a new exercise wrecks you and the same exercise four weeks later does not, even as you get stronger. Plenty of highly effective training produces almost no soreness. Useful progress markers instead: are you lifting more weight or reps than a month ago, is your easy pace faster, do daily tasks feel easier. Soreness that lasts beyond three days or affects a joint is a signal to back off.