Weed, like porn, certainly is something the oligarchs can encourage. Both are spiritually deadening and make men more docile. This is something I noticed years ago in college when potheads would lecture me on weed's health benefits. I've heard the strains are stronger now.
American society is already carrying tens of millions of people who aren't doing anything and have increasingly less to offer in a more complicated work society. Things like farming and secretarial work are more complicated than they used to be. Government failure to stop
the ongoing foreign invasionimmigration of lower IQ people equally unsuited to this work environment brings in more hordes of people who simply drive down wages on these lower rung jobs and who want to join in on welfare handouts. My only guess is that they think having huge population on welfare is a price we pay for globalism. Might as well give them weed and free porn to keep things more calm.
Just to back up your point, Canada is getting ready to legalize mushrooms or decriminalize soon. They are starting with terminally ill folks (experiments), but will surely legalize country-wise at some point: https://www.cnn.com/2020/08/06/world/canada-psychedelic-mushrooms-cancer-therapy-trnd/index.html