How come - watch 7 vs watchos 10

Since upgrading to wOS 10 my series 7 battery life has tanked. W/the same apps n config my watch would run 2 days before needing to be charged. Since the upgrade, the battery life has been cut in half and getting worse w/each passing day. I want my old wOS back. There's nothing in v10 which is worth the current headaches. Apple, please don't try to mimic M$ - it's not worth the grief to your customers...