exit code bash commands env and pwd with an invalid option

Question

These two errors are not treated in the same manner. One has told me that env is not a builtin in bash. Why the exit codes are different ?

pwd -y

bash: pwd: -y: invalid option

echo $?

2

env -y

env: invalid option -- 'y'

echo $?

125

I use GNU bash, version 5.0.17(1)-release (x86_64-pc-linux-gnu). I don't find the response on google. I'd like just to understand it.