Damn, I was thinking about trying to do the same thing...
Discussion
It’s might sill work…location location location.
It isnt really passive if you are stocking the machine, sourcing the drinks, emptying change, responding to broken/unplugged/etc. machines much.
Had 2 of them myself maybe 15 years ago, and I could stock easily since they were at my job. Made a couple hundred a month each, but it was also time involved. NOT really passive 😉