Depends on the type - regular decimation is optional during the build step (you can select any mesh in Unity and choose decimation options on the Needle engine platform tab)
The type of re-meshing that Simplygon, RapidCompact, PiXYZ are doing can be useful though if you have assets with many verts or many parts
typically I’ll have something that starts as a 10-15 mb mesh in blender, which I crunch down to less than 1 mb by the time I import into needle- I know you guys are using draco to do this for me, but I just like to know that everything is default small
by user 962902844049096704
So crazy how far all of this has came in a decade- I remember the struggle when GLTF was brand new, and it was so ridiculously hard to build any compelling web experiences in 3D for the browser. You guys are doing amazing
by user 962902844049096704
Basically our pipeline is designed in a way that you can throw in meshed CAD data and it will “just work” with a combination of simplification and mesh compression. So I’d invite you to try out throwing the 10 MB thing into Unity and checking what it ends up with the automatic pipeline - if it’s larger than what you do manually I’d like to know 
If you’re offering me a simple solution, I’ll take it! Will report back!
by user 962902844049096704