Kant was wrong however. Inher it in as he did the medieval sceptical assumption that reality is 'behind' what we see. Reality is nothing more than the ground of the logical structure of experience - and a structure that cannot be reduced to experience or equivocated with it. The phenomenalist assumption is based on a genetic fallacy that confuses the conditions for knowing something (epistemic possibility) with the conditions for something being the case (truth).
Science is one kind of activity which clarifies and exposes the logical structure of the world, there is no deep metaphysical problem here. Scientism is better opposed on realist grounds, rather than phenomenalist ones: idealism is a very poor way of being anti-reductionist. Not stupid 'behind the viel' realism whinch has mostly been an idealist strawman, but a simple ordinary sort of realism which says 'if has properties, it exists' - taking this to be a definition of 'exists' rather than an argument.