The benchmark for Zstandard against Brotli seems to miss a key information---the compression levels used for both algorithms, because both the compression ratio and compression time will depend on them. In fact this had been my long suspicion about introducing Zstandard to the web standard, because lower compression levels for Brotli are not that slow and it was never publicly mentioned whether improving lower Brotli levels deemed infeasible or not. Given Zstandard Content-Encoding was initially proposed by Meta, I'm not even sure they have at least tried.

Given we now have two strictly better algorithms than gzip, I also wonder about a hybrid scheme that starts with Zstandard but switches to Brotli when the compression time is no longer significant for given request. We might even be able to cheaply convert the existing Zstandard stream into Brotli with some restrictions, as they are really LZSS behind the scene?