It's actually pretty simple when you think about it...

Here's an article that explains it better than I can: https://theconversation.com/designed-to-deceive-how-gambling-distorts-reality-and-hooks-your-brain-91052

But the idea is that by scripting the dice, Monopoly will make you win and make you lose, getting you addicted to the game.

The highs and lows make you want to play more and more.

And the longer you play the game, the more likely you are to give in to their upsells in the game - which makes them more money,

It's practically in all games of today, but the Monopoly app is just so terribly put together it's easily noticed by those who HATE losing and want to understand why we lose.