But then with solar and batteries civilian infrastructure becomes much more resilient against drone strikes.
Instead Ukraine came up with an idea of mass producing extremely simple cruise missiles that could fly 2000 miles and deliver up to a ton of explosives with a cost of 100K and make 1000 of them per month. But then it seems Russia was able to discover the production sites and destroy them.
It's true but they are so cheap that launching a whole bunch and/or improving them incrementally is possible. Yeah they are for stationary targets mostly, for sure. And of course their sounds and relatively low speed does make them somewhat easier to shoot down with short range AA guns and can have automated acoustic early warning system (it's like a flying lawnmower or chainsaw).
Radars can be fooled with this simple physics hack called Lunenberg Lens