The author is located in Italy, where "it's the truth" is not an absolute defense against defamation like you say - basically, here, causing "reputational harm" is actually against the law, even if you are telling the truth. There are a few exceptions like social interest which may apply, but it is a dangerous game to play because you need to prove that to the courts, as opposed to just proving what you wrote is what actually happened.

Plus, any court proceedings in Italy can routinely take decades, destroying one's life even if they are completely innocent, even if the complaint is trivial, even if the complainant is obviously malicious.

It's a curse we also inherited in Brazil. Companies can't have any marketing mentioning their competitors or they face lawsuits.

In the USA it used to be very rare for companies to directly mention competitors in ads. Products would be compared to "Brand X" or some other genericized name instead.

I think it still is somwhat rare. Why even let a potential customer know that a competitor exists?

It's usually some new entrant taking on an old brand so they aren't really helping that brand's awareness.