Comment by xyzzy_plugh

I kind of agree with you, but there's more to the picture.

The situation you describe is kind of already the case with various approaches to compression. For example, perhaps we decide to bitpack instead of use the generic compressor. Or change compressors entirely.

This sort of thing exists without WASM, and it means you have to "transcode" i.e. rewrite the file after updating your software with the new techniques.

With WASM, it's the same. You just rewrite the file.

I do agree that this pushes the costs of iteration up the stack in a vastly less efficient way. Overall this seems way more expensive, very unclear that future proofing is worth it. I've worked with exabyte-scale systems and re-encoding swaths of data regularly would not be good.