draining of battery usage may varies depending on how you use your device. Battery usage on my z3 flip and tablet s7 with april update seems working pretty well.
monitor your battery stats which apps hogging the most of your power juice, identify and try to disable background data usage, please don't disable on your main communication apps.
identify as well on which other apps that you rarely used but draining your battery, either uninstall or put to sleep or deep sleep.
set to automatically turn power saver features on at certain lower battery level so that you can go extra mile.
there are many other options that you can try to disable, to save some juice like turn off location service, background scanning, nfc, sharing features, opt for wifi rather than mobile data etc. A lot of youtube, tiktok videos can offer you more detailed steps on android battery saving tips.
