I don't think the restrictions are doing much for victims. I assume Google was pressured into doing this by the authorities, or may be doing this to get in a good spot politically.
I'm sure making it harder to obtain software outside a first-party app store provides some protection to some users from scams, but I really don't want that to be the answer. I don't claim to have a good one myself.
Just because something is technically possible does not make it a solution