Cannabis legalization & drug legalization have much bigger substance than "people just want to get high" or bodily autonomy arguments.
The drug war is a colossal failure that increases the surveillance apparatus and the police/carceral state, has cost us over a trillion dollars, and has separated a lot of parents from their families and generally has been harmful on families and communities in general.
It has also impacted foreign policy including US interference in elections in other places, impacted the economies of other countries and has caused us to deal with an influx of immigrants escaping poverty or violence caused by cartels which are empowered by US drug laws.
It's also part of the racket of government seizure of assets - civil asset forfeiture & the ways the government increasingly forces paper trails of money, to extract taxes and track how people spend their money.
So people can complain that weed or drug legalization is about people wanting to get high - but every single person in this country (and in much of the world) is impacted in extremely negative ways by the drug war.
Advocacy for ending it is so much bigger than the basic bodily autonomy issue of people having the right to put what they want in their bodies. It impacts public domestic and foreign policy, taxpayers, police and government intrusion on our private lives, surveillance, safety, communities, and more.