Eagle_Owl
I mentioned that it wasn't really a 1:1 comparison of course, I'm aware of that.
Here's the chain of events of the past 2 days and I'll let you judge if the result is to be expected. Two days ago I charged the Pixel9 (limited to 80% with the appropriate setting) around 10:00 PM and I didn't touch it except a few times where I tapped on the locked screen to watch the time and see the battery status. Yesterday afternoon, the battery was already at 72% without the phone being used. Then, I had 2 very long phone calls, about 1h and 2030m each. The phone sitting on the desk, screen off and a USB-C-to-Jack adapter with in-ear low impedance cheap earphones with a microphone for the whole conversation. After the phone calls, the battery was at 36%. The cellular connection was 5G and I had the "[HD]" indicator (the audio was very clean indeed).
Note: I don't have any apps in the background polling the network, no social apps whatsoever, no active GPS, etc. nothing special (only very quiet and well behaved FOSS apps)
So? Is this to be expected? I really don't have a formed opinion, I'm just finding this a bit battery hungry but I might be wrong.