1) meth is highly addictive and there is no pharmacological intervention for that addiction. there is no clinically effective therapeutic treatment for it either
2) meth is neurodegenerative. heavy users end up with a permanent disability
3) at some point around 2010 a bunch of cities decided it was totally cool if dealing and public use were normalized/decriminalized in areas their most vulnerable populations hang out.
(3) is an incredibly stupid and expensive policy given (1) and (2)