Constitutionally, all drug policy should be set on the state level. Of course, not all states will set the same policies. Some may fully legalize. Some may have harsher penalties.
Personally, if our goal it to help people struggling with substance abuse, I believe prohibition --- locking people up --- does not work, including for harder substances. If we want to really help people, let's help them. I would rather pay for someone's treatment than for their incarceration.
You are so right, that it would be better to pay for their treatment instead of their incarceration, couldn’t have said it better!