you, and you can still find a lot of Monopoly slots to play. Although, don’t worry: This isn’t a thing that interests the “end-user”, a.k.a. Only a couple of developers have that kind of budget, and that’s why almost all popular Monopoly slots are being developed by IGT and WMS. This is because of the licensing rights: Monopoly is a trademarked game, and if you want to turn it into an online casino title, you need to pay a (very) high fee.
There are many Monopoly-themed slots, but all of them are developed by a couple of developers.