I am very suspicious of free lunches; almost surely this means the expressibility of QCNNs is limited (as opposed to a sufficient depth VQE)? (Disclaimer: I di

I am very suspicious of free lunches; almost surely this means the expressibility of QCNNs is limited (as opposed to a sufficient depth VQE)? (Disclaimer: I didn't Google for known results w.r.t. the expressibility of QCNNs)