My work laptop is a mbp 2018 (i9, 32GB). The battery life is abysmal. I typically get a little bit over 2 hours. I'm not going to lie though: I'm always running Atom or VSCode and there's lots of opened tabs in Chrome.
I'm impressed; with Xcode and the simulator I'm lucky to get anything longer than 6 hours…
I got the figures from https://en.wikipedia.org/wiki/MacBook_Pro#Technical_specific... and https://en.wikipedia.org/wiki/MacBook_Pro#Technical_specific...