Yikes. That sucks I'm sorry you have to deal with that
The 14" is indeed the black sheep battery-wise of the Apple Silicon family. It's still good (relative to Intel/AMD/anything else) but it often falls short of being great...
I'm only surprised that you're on the M1 Pro and not the M1 Max as the battery drain (even when doing nothing) is even faster on the Max due to the doubling of memory bandwidth (uses way more power.)
My M1 Max spends most of its time plugged in and it's battery health has been stressing me out. That said it's only at 93% according to Apple and 90.2% according to Coconut Battery. My use case will be shifting in April to using it more on battery so we'll see how it holds up in the coming months.
Assuming you bought on or around release your results are much worse than not only my 14" but also the thermal modded MBA I previously owned (which was close to, but not at 80%.)
Could you give us some more info on your use case/situation?
Ex:
1. Do you typically use your MBP on battery? Power Adaptor? A mix of both (and if so roughly what ratio?)
2. What applications do you typically use and for what kind of duration?
3. Do your workloads tend to get your MBP's fan running / get it hot?
4. Do you have AppleCare+ and or have you taken it in to get diagnosed (pretty sure this is "defective" in the sense that unless you've somehow modded your machine there's no way your battery should be at 80% less than 18 months after release)