Australia and NZ both have prostitution legalized with a bunch of European countries.

When I came to US I was amazed that guns and weed were legalized but not prostitution. Even in Vegas.

I'm sure there is plenty of underground prostitution in US where the workers have little rights and are probably abused.

I have no hopes that this will ever happen in trump administration but hopefully in 2020+ this could be a possibility.

weed is not legalized in most of the country, and even where it is "legal", it's a complete gray area. It's illegal federally, which completely overrules the states' ability to legalize it. Basically all the legalization you see is that the local state/county police will not come after you for it, but the DEA is still perfectly within their right to come after you if they wanted to - which has happened to some dispensaries.