@QueerMatters connective tissues get worse with age... and hEds gives a headstart. Some experience a brief improvement because the tissues get stiffer and allow less movement, before their condition worsens - but overall, yes, age isn't kind. That plus muscle loss, the muscles don't hold the joints properly anymore.... It's all kind of reversible with proper training, weight lifting especially for muscle mass and tendons/ligaments health.

Also a lot of factors can pile up, hormones, viral infections... we know that those can cause short and longterm worsening of symptoms.