Do you really think adding just 3mm to the battery would do that?
In general smart phones are not going to last much more than a day. That they last a day is good enough to stop battery panic.
If a phone lasted 1 1/2 days, enough to convince you to not plug it in at night you would still have battery worry on day two.
I just bought an M2 air rather than a pro for my coding. It functions great. In my desk it’s fine. On my lap it’s uncomfortably hot after a long compile.
(That said if I asked somebody in Apple marketing they would probably suggest that the pro is there for people like me. )
Apple need to differentiate the pro from the air. Start at 16Gb maybe.