The moment I started coding heavily (multiple simulators, multiple terminal windows, VSCode, Postman, Linear, Chrome, Slack), it's performance and battery life became as bad as my 15inch from 2017.
There must be something sucking down memory, possibly an app designed for intel architecture. Did you check apps using significant energy? I had one or two surprises in there before.
If you look at energy impact in activity monitor you might find your biggest consumers are intel architecture programs. You shouldn’t be getting battery life that bad.