No hard data to show, but I confirm that battery drain seems to be worsened with Android 11 on my A40, with the exact same usage patterns than before the upgrade
I'm experiencing this as well on my A71, when I was on Android 10 by phone would loss just 1% overnight if even that. Now on Android 11 I loss as much as 12% overnight & nothing I've tried resolved the issue.
Not of these worked, even if I power off the phone overnight it seems to still loss about 3%. Device Care battery statistics doesn't seem to show what's causing this drain.
On a side note.....I don't like the new power saving mode on Android 11, it sucks compared to the previous one from Android 10. This seems like its a system problem that Samsung should fix, should have known something was up when I got the update early, I never agreed to be a beta tester!