The battlefield is one of the things every new Magic player learns early on.
While layouts can differ slightly at times, they all have the same zones: There's the battlefield (where creatures, artifacts, lands, etc. are), exile, graveyard, command zone, and so on.
While the traditional game still has the same zones to this day, a few expansion added in some areas. However, all these expansions were from sets that didn't really share continuity, namely, the un-series. Unstable in 2017 brought in the subzones of contraptions, sprockets, scrapyard, and one zone only mentioned in the card AWOL.
Unfinity five years later had a few other one time zones and subzones too: Attraction deck and junkyard. But it also wasn't the un-series. Mystery Booster in 2019, the set that tried to make chaos drafts more cheaper for players, also introduced some of these. The whammy zone, aka, the additional deck zone, as well as the interplanar battlefield. However, none of these really stayed. They were all one offs, and none really tried to add a new zone in permanently. But there was one that they were looking into: Midway.
Midway was supposed to be in Unfinity. But unlike all these other one off zones, midway was experimenting with a section of the battlefield dedicated to a place any player could use. This was a bit of a test but...it also didn't come to completion, and is the only unreleased zone in Magic history. Why? Well, when tested, they simply didn't like how they had to pay for something in a game if it could be used against them.
According to Mark Rosewater "You have to design cards such that a player is encouraged to put them in their deck. In Unfinity, attractions originally went to the midway, a section on the battlefield, that any player could use. Players just didn’t play them because it wasn’t fun that you pay for something that your opponent uses to beat you."
Perhaps there simply was no meeting midway on midway.
