Are we weakening optimization of forms by introducing JS?

[martinLechnerShopify]

Today websites optimize their forms (hopefully) so that Autofill can fill them. This helps us capture new addresses and offer the user to save the addresses. If websites don't need to optimize forms for filling anymore, we may regress at
a) capturing new addresses and may not be able to offer filling as much in the future.
b) learning how users represent their information (if a user submits an address for the first time, we only see a structured or unstructured representation and need to guess the other one; we learn/refine it later from form submissions).