Comment by SoftTalker

Agree, static HTML seems the only thing that is at all future-proof. Any hosted blog or platform will have the risk of shutting down or abandonment but if your source is HTML you can host that anywhere, with little setup. Even so I'd keep my posts in a text-based precursor format such as Markdown or Org-Mode. I don't think HTML is going away soon but it's not inconceivable.