Black Hat SEO isn't dead, but the glory days of flooding your site with traffic with just a couple of tricks are over, the dirty SEO of shoving hidden keywords or buying links en masse no longer works like it used to, techniques that outsmarted the algorithm in 2018 are now a death sentence for your website.
The thing is, google has become incredibly smart, and now its algorithms understand language and context better than ever, you can no longer fool the crawler with obvious tricks, these days, what exists is Gray Hat SEO, which consists of techniques in that gray area that are on the edge of the rules but don't quite cross them, things like using high quality link farms not the usual cheap ones or automating certain parts of link building on a massive scale. If you know what you're doing and are careful, some people can still profit, but most who try these techniques without the proper knowledge end up sinking their projects.
The main problem with starting with Black Hat SEO today is that it's no longer profitable for someone just starting out. You can make quick money, yes, but you won't build a lasting business, most sites using pure Black Hat SEO last a few months before being wiped out with an update.