My iphone 6S has poor battery performance after updating to iOS 14.3

It drains the battery in about 2 hours! I chatted with an online agent, no help. I visited the genius bar, not help. ThenI go on google and discover this is a common problem with the 14 updates. Why did no one working for Apple mention this, and what do I do about it? My phone is useless with a battery that discharges so quickly. Can I go back to an earlier version of the IOS?