Should Developers Use An Existing Blogging Platform Or Build A Blog From Scratch

um... i always say... just use something free at first. you can always move later.

like IH! https://www.indiehackers.com/post/3-ways-to-use-indie-hackers-as-a-project-product-blog-f6fc367485

I would say it depends on how confident you would be in coding what you need. I recently set up the blog for my SaaS Adflow.ai, and I went with a light-weight solution that just reads from .md files (background story here).

If you think you could create your own solution in half a day to a day, then you could as well just do it. Otherwise, you can try one of the many off-the-shelf solutions.