Casting this card for X=2 on turn two happens more often than you might expect
Even still, people do it
Until end of turn, you may play the card you own exiled this way and each other card exiled this way with lesser mana value than it without paying their mana costs
Because the land enters tapped, Vibrant Cityscape is best used early, before tempo matters, or late , when triggering landfall becomes the priority.
Its an all-around fascinating support card that can quickly snowball into a massive game-ending threat
Almost entirely because of duplicate protection, they have now 100% lured me in as a customer to start seriously playing on MTG Arena and spending money, while also still collecting Common, Uncommon, Rare sets on MTGO (though no longer Mythics, it's too expensive to keep that up)