I mean just looking at numbers is almost pointless. Cats usually live near cities or rural population centres and take out small/tiny birds. I doubt many care about a cat taking out a pidgeon or common sparrow/finch, there is already an overpopulation problem of these birds in cities thanks to a lack of natural predators.
The main problem with cats is when they end up in the native habitats of endangered small birds, which can lead to massive consequences, including extinction of the already endangered small birds. That's the big problem with outdoor cats, when they end up in those situations outside of major population centres, where they can inflict serious damage on biodiversity and ecosystems.
The problem with wind turbines with birds, is that they can be placed far from civilisation and take out large apex predator or scavenger birds, many of which are endangered. As well as the potential habitat loss of building a wind farm in a certain area. The article even mentions that.
While the relationship between wind turbines and different types of bird populations, particularly apex birds, is understudied, there is some evidence that turbines can hurt those populations. Hawaii, home to many endangered species, has taken extra steps to protect species that could be vulnerable to wind energy. The state requires all potential wind projects on both private and public land to have permits and conservation plans for the bird and bat population. Hawaii also documents animal mortality data from independent, third-party experts, with some wind farms subjected to steep fines for killing any federally protected birds.