I checked my VST3 folder… the most space required, the NI stuff, followed by the Arturia stuff.
It all comes down to NI again.
And some vendors installed the AAX plugins with no way to prevent it. It costs 2.3 GB on my system, without any need. The same goes for some VST2 stuff.
But we discuss this in the Steinberg forum…
We should make the vendors aware of these “issues”.