I've had battery drain issues since iOS 14.0 on may iPhone 7 Plus. This is mostly obvious overnight. If I leave a fully charge phone unplugged overnight I would find 50% batter drain. If I check the Battery history for the activities during the night I'd see an obvious linear decline along with a single random app using 0min on Screen (which was strange to see). Since updating to iOS 14.2 I've found the battery drain issues appears to have gone. Last night a fully charged phone only went down to 75% which is normal and checking Battery history there was no apps for the first time triggering any overnight events. I hope others experience this improvement, too!