The statements made in the article are simplistic. Sure, it may seem fullstack, but there is also a popular mantra "Focus on your strengths, outsource everything else". So, sure you have a marketing person, but now how many SaaS tools are we buying to get the marketing going? You may not be outsourcing the entire marketing, but you are now hiring someone to run the marketing by buying up 5 different SaaS tools. This doesn't completely replace the outsource, but to call it a fullstack sounds overly simplified.