Depends what you are selling and to who. If you are selling to teenagers, then yes, a website probably does not matter. But if you are selling serious things to business, then a website is not enough, that is true, but it is a cornerstone.

I like the diagram of "The New Online Business Model", except that it should include a website. And busienss users don't generally pay much attention to twitter either, or Substack. They tend to read Medium, and LinkedIn, and a large number of domain-specific content. A big challenge is getting your content into those domain-specific sources, because they have become pay-to-play to a very large extent. There are hidden marketing machines that push domain-specific content people through newsletters and emails.