Have you checked how much battery each app is using? App updates/device firmware updates can sometimes cause the same apps/devices you've been using to eat more phone battery. Like, it happened recently with a Facebook Messenger update, whose previous update kept randomly rebooting my phone up to four times a day, and then they fixed both issues. And with a Bluetooth medical device I use, suddenly the app started draining my battery like crazy after a device firmware update and app update, and they've only partially fixed it (no new firmware update for the device yet, but the app update did lessen the battery use a bit, just not nearly as low as it used to be) - it was using up to 40% of my phone battery at one point, whereas before it was using like 0.6% each day. It isn't something I can put in deep sleep like Android Settings keeps suggesting.My Fold 3 is now running down much faster. It's now only just lasting the day, where it was lasting two days when new with just about the same set of apps.
I'm hoping that Sam will have good tradein deal for the Fold 4, don't fancy getting new batteries for the 3.