https://wiki.bitmessage.org/index.php/FAQ#How_does_Bitmessage_compare_to_other_messaging_methods
check the last modified date on that page
no but if PoW was part of its strategy it was doomed from the start
here's some history for you, since you think i'm being facetious
https://wiki.bitmessage.org/index.php/Main_Page
I wonder why this was frozen in time at 2016...
Discussion
Adam Back made hashcash, the origin of bitcoin's PoW and also Bitmessage
note how that's a HTTP not HTTP address? that's how long ago it was abandoned