Steam - Poe2 is listed as an MacOS Game

Steam lists PoE2 as a Mac compatible game, and lets you download all 112GB of data, but then when launching says it can't find the exe.

Obviously, PoE2 is coming to Mac at some point, like PoE1.

But letting potential players download a very large unusable game is not a good look for GGG.

Seconded. I got hit by this the other day. In my Steam (Mac) Library view in the left panel, Path of Exile 2 shows as available (there's no 🚫 icon next to the game) and the Install button. is available. So I had exactly the same experience as OP: a large download followed by a game that can't launch.

This seems like a build pipeline bug: someone got a preliminary skeleton of the Mac build in place, but it shouldn't have been uploaded to Steam.

The store page for PoE 2 still only says it has Windows support, but once purchased that info is no longer front and center anymore. The Library view takes precedence.

FWIW, there's a fair community of Mac gamers like myself who will jump in on a game in Windows-only Early Access, anticipating later Mac support. In the meantime, folks will play on other hardware, a Windows VM, or via CrossOver Mac.