Do under eye bags get worse as you get older?

YES!!! Nothing gets better as you age. Sorry, that's all there is to it!
Treat aging eye bags. Aging of the lower eyelid allows the fat of the lower eyelid to form a bag. There are no preventative measures but treatment includes surgical removal of the fat with release of thje arcus marginalis and fat grafting or tear trough implant to improve the contour. I perform the surgery from outside or inside the lid and recovery time is around 2 weeks.
Eye bags/ageing. That is called aging and increased laxity of the lower lid tissues allowing the fat pockets to be more noticed. See in person a few surgeons.
Yes. As we age the connective tissue gets lax and we tend to loose fat volume in the face. This makes the appearance of bags under the eyes worsen.
Lower eyelid aging. Yes, several factors contribute to this including the increased visiblity of the fat, laxity of the skin, prominence of the muscles and expression lines as well as descent of the cheek fat pad and prominence of the tear trough.
Yes. Bags under the eyes are pockets of fat moving forward due to loss of elasticity in the skin and fibrous tissue under the skin. As we get older this loss continues and bags prolapse even more. There is a surgical solution to permanently remove these bags and tighten the skin.
Yes. Gravity, and age-relate skin changes will usually emphasize the bags under the eyes as one ages. Blepharoplasty is a good solution to this problem.