I've an iPhone 6s with similar fast battery drain issues after 14.2 as others are reporting.
The problem seems to be fixed after I recalibrated the battery percentage reading by draining the battery until it reached 0% and the phone turned itself off. I then charged phone to 100% and repeated the full battery drain. After it was then charged to 100%, battery usage percentages appear to be back to normal.
quilter23
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