A way to pass a defined list of handles to a subprocess (or a friendly other process) makes sense. Having that mechanism be direct inheritance of those handles with the same numbering as the source is obnoxious.

That’s like saying you could use positions to specify function argument access (as in assembly) instead of variable names. File descriptors being numbers that are likely array indexes in a file handle seems like a leaky abstraction. Having a namespace that a parent process share with its children seems like a much cleaner design.