Xcode 26.2 is a 2.1GB download, which expands to 8.63GB on disk, which includes the macOS SDK. The iOS SDK and simulators are another 8.38GB. Luckily Xcode versions can share iOS SDKs now, so you only need to install them once. Really the biggest disk eater is Xcode's default behavior of creating a huge set of simulators for every platform.

You’re counting the development SDK against the IDE. Xcode itself doesn’t require that space, and you’d need that space regardless of IDE choice if you were targeting the platform.

Indeed, and unless that changed since, the Mac downloader isn't even capable of resuming downloads properly so if anything happens while you download these 13GB, it's back to square one.