Not sure if I misunderstood, what are the chances those different consumers / tools / operations are running in your memory space?
You still have to transfer the data, but you remove the need for a transformation before writing to the wire, and a transformation when reading from the wire.
The key phrase though would seem to be “memory representation”m and not “same memory”. You can spit the in-memory representation out to an Arrow file or an Arrow stream, take it in, and it’s in the same memory layout in the other program. That’s kind of the point of Arrow. It’s a standard memory layout available across applications and even across languages, which can be really convenient.