I noticed same problem on 6s. My battery is above 80% health and can not last more than 5 hours of normal use. It lasted whole day with same use before update to IOS 14.1. Also, battery is fully charged for about 1 hour (incredible fast, never so fast untill now).

I instaled 14.2 on 6s and same problem. Battery drain for 2 hours!!! I was think about fast resolve this bug, but now I see that I have to buy Android. This is very unserious by Apple.