Yeah, at first I saw a handful of people talking about their low batteries and ... we get that every year - usually a few people who have really bad battery life, but the 12 had more than just a few - it still isn't a TON but it's more than a few.
My wife's 12 Pro Max and my 12 Pro Max both started out at 104%. She has 2x the cycles I do and uses MagSafe 100% (I use wired - anything I can find, batteries, 20w, MacBook charger, or an Insignia wall plug). Now, almost a year later, she's at 93% - it's dropping fast. I'm still at 103.9%.
Some here still have 100%+ and use wireless. Some have low % and use the 5w.
I know you didn't ask me but what I would do?
The 12 Pro Max is the first phone I paid for outright. I've been on the Apple Upgrade Plan since it started (until the 12 Pro Max). So I paid for 2 years of AppleCare+. I'm going to get my $ worth out of this phone. I'm going to use it for 2 years then trade it in next year for the 14. (Looks like the 11 Pro Max goes for $500 - so for the iPhone 14, a 12 Pro Max should go for around there).
Did you buy AppeCare+? I would run the phone down to under 80% and demand a replacement, then trade it in for $ next year. That's what I'm going to do especially if my battery drains hard next year.
I'd get my money's worth out of it.
That said, I've seen the other side (Android - I came from there long time ago) and I still decide to stay Apple - I don't think Apple goes out and tries to cheap out on batteries - their hardware is usually premium - but it is good to know what the other side of the fence has - grass appears greener but each side has their problems.
Look at the world of EV batteries - GM is having to recall LG batteries due to Bolt fires - going to cost them billions. Batteries are having issues because we're pushing them harder and farther than we ever have before.
My .02