Apparently, the RK3588 has a hard gzip/zlib/deflate/lz4 decompressor module.
I have to admit, "i wish i could offload this to a hardware accelerator" has not been a thing i've thought when using gunzip (or unpacking gz tarballs in general).
(Like, give me a hard xz compressor ... but gunzip? lol)
(And yeah, as you can expect, the linux kernel has no support for this... atleast in upstream, i didnt check rockchip kernel, hm..)