> being an employee (in the UK) resulted in significantly more taxes than being self-employed

Why would this be the case? I'm not challenging your claim, I'm just curious. Is the idea that the UK wants to give tax breaks to small businesses?

> Europeans almost never have comparable healthcare costs to the USA, so that part isn't universally true either.

Not sure about self-employment, but American professionals take home (i.e., after taxes, healthcare, and retirement/pension) considerably more than their European counterparts. To the parent's point, it's quite a lot more difficult for an ordinary (i.e., not-self-employed) American professional to get wealthy by following the approach outlined in this article, but it's quite a lot harder still for our ordinary European professional.