Emulator

there nothing wrong with the current system the gains are negligible. and i dont see anyone complaining about the format

Resource pack creators want to ship compressed archives, not uncompressed, as the file size reduction is quite substantial for DDS textures. They don't want to use deflate either, they seem very insistent on using LZMA2 with 7z.

Forgot to add: this is just based on my observation of most texture packs not actually supporting the resource pack system. Some even include the manifest.json, but provide it as 7z so you can't actually use it as such without repackaging it.