People tend to forget why cycling shorts have "padding".

Of course the use of bicycles for racing predates many of the modern fabrics that we now use. So the actual materials have changed even though the reasons for their use remain the same.

Early cyclists could become blistered from the friction between wet sweaty skin and cotton shorts on the leather saddles. Although natural sponge was tried... this didn't resolve the moving friction problem because the sponge soon became soaked and compressed. Instead... layers of very soft goat or sheep leather (called chamois) was used. This chamois (pronounced Shamy) would stick to both the skin and the shorts but allow the movement to be absorbed in the layers of leather.... preventing blisters. The soft chamois also provided a level of cushion as well.

Modern materials... like closed cell foam work very well and don't require the oiling and special handling required of the old natural chamois. But the purpose remains the same... to absorb the friction/movement between cyclist and other materials including the bicycle. Not... as cushion. Some people also prefer to use a grease or lotion like lubricant or powder to help reduce friction.

Aggressively cycling in cotton briefs and jeans can still cause blisters, skin removal, and [carpet] burns in rather sensitive areas. But less aggressive... sit up and beg positioned type cycling requires little or no special clothing or precautions for most people.