At least for medical purposes I might add. Here's why:
Cancer treatment
Marijuana can be used in many cases. For example, my grandfather had cancer and after like 4 chemo therapies he was felt so sick, he couldn't eat. Every time he ate something, it wasn't too long and he puked. I don't say Weed could have fixed it, or if it would've even helped, but I think it would've been better if they at least tried it. In many cases this helped, but the doctors were limited to the laws.
Pain management
Other example, pain management. Many studies are ongoing if and how marijuana can help people to manage pain. Many studies for short-term effects confirmed that marijuana helps you to feel less pain after an operation or something else, if you don't want to take opiates.
Depression treatment
Studies have shown that medical marijuana can lower the impact of depression in your life. Research institutes are still studying the long-term effects but right now, marijuana is used in some Asylums.
So all in all, marijuana still needs more research, but in the mean time it could be used for cancer treatment or pain management.
As always, do your own research in this topic. Only my opinion is reflected in this article and yours might differ. This should just be a little insight so you can inform yourself, if you find this topic interesting