There are two reasons to have your bathroom renovated: 1) your bathroom doesn’t look the way you would like or 2) it was not built to last in the first place. For the first reason, people usually just say that it isn’t that important, if it is functional then it is fine. But think of this, the average person spends more than a year and a half in the bathroom in their lifetime. Given that, it’s not surprising that so many people want their bathrooms to be pleasing to the eye, as it is a chance to get away from the daily grind.
As for the second reason, your bathroom contains a lot of moisture so it is important that it is built to withstand that humidity. If not, then the dampness may seep into the underlying material weakening the material and cutting its longevity significantly. Worse still if excessive moisture really gets under the floor and behind the walls then there is the possibility of mold and mildew which can cause a number of health issues.