Legalization mostly works in the way that more people consume it. (punishing the use does not lead anywhere either).

Legalization of cannabis in the The Netherlands lowered usage amongst teens. Making pot less accessible to teens was one of Trudeau’s primary arguments for legalization in Canada. Street dealers have a lot of reasons to not ask for ID.

This was proven false by the Portuguese drug decriminalization program.

Decriminalization is not legalization, though. It still makes it harder to access the stuff, for example, and risky to grow your own.

Not that it's especially hard to buy pot in Portugal, but still, can't exactly get it at the corner store.

There are very definitely ways to do decriminalization that result in lowered usage: Portugal and heroin is the standard example.