His main points are about accessibility but there's a lot of overlap between accessibility and SEO. Google needs semantic tags to understand your site. It will

His main points are about accessibility but there's a lot of overlap between accessibility and SEO. Google needs semantic tags to understand your site. It will treat any <a> as navigation and won't do the same for <button> or any other approach. The basic premise that <button> is for CTAs and <a> is for navigation is the golden rule. You can style either anyway that you want.