if just after update then wait for few days and meanwhile do these steps
A. Wipe Cache Partition. Steps to perform. 1) Turn off the device. (Connect with type C cable/type C earphone only for Android 11) 2) Press and hold the Volume Up key and the spower button. 3) When the Android logo displays, release all keys. 4) Press the Volume down key to navigate and select "Wipe cache partition". 5) Press Power key to select. When the wipe cache partition is complete, Select Reboot System. 6) Press the Power key to restart the device.
B. Reset App Preferences. Settings >Apps> Tap on Top Right 3Dots and select Reset App preferences.
When did you update?, can you try wiping cache. Battery life is fine here. Getting max 7hrs. 15 mins in 120hz. Its first stable a11 update so battery life wont that great as last build of a10. Battery life totally depends on your usage.
Its quite early to confirm the battery life of your device after a major update. You need to give it alteast 6 to 7 cycles to make kernel adapt to your usage. That means you can judge battery life after some days. Its too early to start complaining about it now. Please check it after a week and see if it improves. Have worked with kernel developers, give it some time for the kernel to adapt