I successfully did a super massive compress file, from 513MB model with 88000 verts and a huge amount of shape key animation into an 8.04MB Gzip file format(Gzip is the best way to compress glb file and performance will be the best in the web browser and it will automatically unzip itself).
With huge amount of compress, i was wondering will the result be tragedy?
But the final result is amazing!!! looks the same as original 88000 verts mesh! I use "simplify" command from glTF-Transform package, from 513MB to 45MB !!

And I use the glTF-Transform CLI package, super easy and useful!!
Ask me anything~