I'd say blogging on a "platform" as opposed to a self-hosted/controlled solution would have some benefits over a self-baked one.

But at the end of the day, if you're blogging for your business/startup it makes more sense for it to be under your control as you can leverage the analytics and if possible turn them into conversions.

What surprised me most about the speed stats in your image is the file size of the pages. The medium.com page is half a megabyte! And yet it's a plain text page. What's causing the bloat? Are fonts being downloading? Even if they are, it's still feels excessive.

Possible true, but that's a tad too technical for me. I just want to focus on the writing.