Of course cannabis has medical value; the FDA has approved pure THC as a pharmaceutical, and the cannabidiol in whole cannabis has its own therapeutic applications and also protects against some side effects of THC. So denying that natural cannabis has medical value is nonsensical.
But equally of course, the variation in natural cannabis means that “marijuana” isn’t the name of a medicine; a medicine is a material of known chemical composition that has been shown in clinical trials to be safe and effective in the management of some condition in some group of patients.
Some sick people get relief from whole cannabis, but “medical marijuana” is a political fraud, and the “medical marijuana” business is mostly a sham, with most of the volume going to non-medical users – many of them with diagnosable cannabis use disorder – and resellers.
Footnote In a Twitter exchange, MPP lobbyist Dan Riffle doesn’t deny the facts, but seems to prefer that I use some euphemism for “fraud.”