Hi & welcome! Dracaenas are sensitive to fluoride in tap water, and can get a toxic dose over time. Tap water also often has lime in it, which can raise the PH of soil over time if not watering thoroughly (so a lot of water runs out of drain holes) often. Simply running out of room for roots to grow can cause issues with the foliage too. Whenever possible, use rain, distilled, or condensate from a dehumidifier or A/C. If it's been in the same soil for 2+ yrs, repotting would help too (chop off the pancake of roots at the bottom of the root ball if found, remove old soil, replace with new.)
The spots in the 2nd pic could be oedema (a cosmetic issue,) or related to fluoride toxicity.
