Tyler Skaggs good. SKAGS on search ads bad. I agree with the article. Too much mess. Harder to make adjustments. Dynamic keyword insertion is a way better approach.
SKAGs, or, Single Keyword Ad Groups, are popular with some search engine marketers. But despite the simplicity of targeting with SKAGs, they're not for everybody. Here are some of the problems you could run into with single-keyword ad groups in your campaigns.