And this is a woefully inadequate theory of modality. It's incompatible with our modal intuitions. So, what the conventionalist really needs to do, is to be an eliminativist about modality, not a reductionist. But, then, they run up against the fact that modality is a presupposition of fundamental practices, as I argued before. But, then, I think that this conventionalist impulse is a product of extreme empiricism, and that extreme empiricism in general is incompatible with fundamental practices.
Necessity has different sorts of grounds in things.
But this is not the only grounds of necessity. I have problems with such entities. I see no reason to posit such entities. If I discern this LED's being on, this seems to me to consist in a concrete particular having a certain feature. The LED and the feature are constituents of this state of affairs that I am visually detecting.