I’m throwing my hat in the ring here, regardless of ANYONE saying “I’m fine on x device!!!” (no pun intended).
2018 iPad Pro user, XS Max user, both running 14.2. If you haven’t updated already, do NOT update until they put out a public version of 14.2.1.
Although I have no personal experience with this battery issue, 1) I am literally always in the house, with the opportunity to fast-charge my iPad whenever; 2) I use my XS for <30 min a day, as it’s got the classic eye-burning vertical green stripe from a drop. (Retina Display takes on a whole new meaning!)
Here’s what I HAVE had an issue with: 14.2 RUINED my smart home. Thank god, my only accessories are lights and light switches (+ my Roku TV), but—despite deleting several automations, they still fired off (this included a Good Morning automation that turns on all the lights at 7:30…in the room my brother happens to be sleeping in as he thrashes through finals week). I had no control over my light schedule, and that’s something I need delicate control of, as my household consists of two tech nerds (me/my brother) and a borderline-Luddite (my grandmother). Had to do a hard reset of everything—including my TV, because resetting HomeKit from its settings was not working. (Perhaps I could’ve avoided this by removing it as an accessory from the Home before resetting. I digress.) Mind you: I have professionally calibrated my TV settings. It was easy enough to take a photo of the settings and recalibrate, but…godd*mn. The absolute most un-Apple-ish thing I’ve experienced in years.
Wait until 14.2.1 y’all. Just. Wait. It’s worth it; the extra features you get in 14.2 are, relatively, not worth it. (Adaptive Lighting was the most exciting feature for me but I expected it to combine adaptive color with adaptive brightness based on time of day, or at least based on sunset/sunrise—not the case. Oh well. Still cool but yeah.)