Will the wardrobe next to the toilet become moldy if it is not moisture proof?

It probably will, especially during the rainy season and the humid summer season, which is more likely to get moldy, but you can try two or three packets of activated charcoal in your closet.

Activated carbon is a very fine carbon particle with a large surface area, and there are even finer pores in the carbon particle - capillaries. This capillary has a strong adsorption capacity and is in full contact with gases (impurities) due to the large surface area of the carbon particles. It can play a certain role in removing formaldehyde and removing moisture.

Yes, especially during the rainy season and the humid summer season, it will be more likely to mold, but you can put two or three packets of activated charcoal in the wardrobe to try.

Activated carbon is a very fine carbon particle with a large surface area, and there are even finer pores in the carbon particle - capillaries. This capillary has a strong adsorption capacity and is in full contact with gases (impurities) due to the large surface area of the carbon particles. It can play a certain role in removing formaldehyde and removing moisture.

This phenomenon will not occur when the toilet is waterproofed.

If it's a public place or a bath, a gym, it's hard to say, it depends on whether your location is underground or aboveground, if it's underground, there may be a problem, if it's on the ground, there should be no problem with waterproofing.