What argument? Most of the article says "Everyone who disagrees with me is a far right gender fascist and also for some reason racist and I'm right because science (I didn't care to link to) says so, trust me bro."

The only half viable arguments provided (and I'm really reaching here) can be easily debunked.

She was assigned female at birth.

Sex is assigned at birth based on external characteristics aka primary reproductive organs, you can't tell someone has internal testes, xy chromosomes or abnormally high testosterone levels just by looking at them.

She is eligible according to the Olympic rules.

The Olympic rules that were changed recently by removing the requirements for testosterone level within a certain range, the same reason why she was deemed illegible to compete by International Boxing Association just a year earlier, who is way more qualified to set fair and safe boxing rules then the International Olympic Committee by their own admission (PDF warning). Clearly we can't say that it's 100% fair and safe for her opponents.

She has lost before

I'm a guy and I'm 99% sure I would loose to a pro female boxer in the same weight class, because I have 0 training or experience, but I'm also 99% sure I would do way better than a girl with 0 training or experience. Loosing doesn't mean you don't have an unfair advantage.

Even using the lefts' own logic, if sex is a spectrum and she as someone who's intersex is somewhere in the middle of that spectrum, isn't it unfair and unsafe for either her or her rivals to fight each other when they're so far apart on the thing that's so detrimental to defining ones' physical capabilities?