That still seems unnecessarily nitpicky and like it misses the point of the parallel. I'm reminded of the running joke on Californication:

"This is Santa Monica Cop. It's my innovative, original series about a hip, streetwise cop who brings his own brand of policing to a much wealthier area than he's used to."

'Oh, like ... Beverly Hills Cop, then?'

"Nah, you're not getting it! See, it's in Santa Monica!"

Yes, S3 doesn't natively allow retrieval/upload via the FTP protocol. But at the level of abstraction of "what does this service do for me, and why would I want to dig into the docs and incorporate it into my system?", the FTP analogy communicates the use case.

"This is S3. It's a way to map a bunch of keys -- which look like directories and naturally follow a kind of hierarchical structure -- to opaque blobs of data, allowing CRUD operations."

'Oh, like an FTP server, then?'

"Nah, you're not getting it! See, you talk to it with a different protocol."

"binary" and "blob" storage makes it even more confusing IMO. How about "file storage where you can only ever read, write or completely re-write (but never only partially modify) an existing file and there are no directories but the file names allow slashes so you can fake directories, and paths are called 'keys', where all the files you upload are publicly accessible via HTTP if you enable that and otherwise are accessible via a widely supported but annoying REST-based API and signed URLs, and where only download bandwidth and monthly storage (but not upload bandwidth) is billed, and is billed based on exact usage with no minimum recurring fee". I guess that's too long though.

"File Storage" is a bad idea for the same reasons comparing to FTP is. It might work for a near layman, but it can actually communicate misinformation to someone who knows slightly more about storage. Specifically, S3 is Object Storage, as opposed to File or Block Storage.

This is why "simple descriptions" are hard. Leaving nuance behind makes a lot of room for confusion.

Since S3 was more or less the first service to have the concept of Object storage, I think we would have been able to deal with ‘File’ storage.

Also, I think the difference is more between filesystem and object storage. You are still uploading files to both.

Yes, I'm still waiting for an "unlimited pay-as-you-go SFTP service" that uses something like S3 as a backend, but you connect with SFTP.