If Apple allowed other App Stores, they would have to make Xcode not suck.
It doesn’t. Xcode project files are something that look a bit like a cross between JSON and an INI file. This is unofficial documentation showing what it looks like:
http://www.monobjc.net/xcode-project-file-format.html
That isn’t a property list; it’s something inherited from Project Builder from NeXTSTEP, which Xcode was originally based upon. Xcode project files would be a lot easier to deal with if they were property list files, because they are a standard, documented format with official tools to work with them. The Xcode project file format isn’t officially documented and doesn’t have generic manipulation tools like plutil.
Maybe you are mixing the project file up with the Info.plist file? That is a property list file, but its purpose is to tell the operating system about the application. It’s not the Xcode project file.
Good news! You don't have to imagine! You can live this fever dream yourself by using Xcode.
How a company with that much money can unironically produce such dumpster fire garbage of a so-called IDE is beyond my comprehension.