Seems like a case of “let’s agree to disagree.”

But for your point about “old fashioned bloggers missing out on organic reach”

That’s irrelevant.

You can link a domain name to Medium and leverage SEO just the same as you would with a WordPress site.

Medium’s high domain authority with enable you to rank faster and easier than a WordPress site starting from zero.

Every possible argument you can make, I can crush.

The only leg you have to stand on is ownership vs 3rd party. And that leg is amputated.