/usr/bin/python3 を単に、python3 と書けないの？

WSL2, Linux なら、
Ruby は、anyenv で入れた
which ruby
/home/ユーザー名/.anyenv/envs/rbenv/shims/ruby

which python3
/usr/bin/python3

ファイルの形式
file /usr/bin/python3
/usr/bin/python3: symbolic link to python3.6

file `which python`
/usr/bin/python: symbolic link to python2.7

file `which python2`
/usr/bin/python2: symbolic link to python2.7

file `which python3`
/usr/bin/python3: symbolic link to python3.6

readlink -f /usr/bin/python3
/usr/bin/python3.6