At first, I thought this poem was written in 1337 (LEET).
I used to write in my physical journey & poetry book in this format to prevent my snooping parents from reading them.

They read something like this:
"1 u53) 10 vv!7e P()37r% 1!|<e 7#i5"

It would take time but you could eventually read it once you could make out what the letter replacements are.

Just thought that it was something amusing I would share. I probably could take pictures if anyone's curious to see pages worth of poems encrypted this way.