Lots of hotels use some variation of cotton for their bedsheets, typically a high thread count, long-staple cotton. Hotels use cotton sheets for a multitude of reasons, including cotton’s durability, softness, and breathability.
Cotton is also hypoallergenic, so hotel guests aren’t at risk of allergic reactions or irritated skin. Plus, the material is machine-washable because hotel staff can’t dry-clean or hand wash hundreds of sheets every day.