Business liability insurance is standard practice for those operating a foundation (the post calls it nonprofit but afaik that's not the same thing unless they intend to apply for ANBI status, after which you can donate tax-deductably, at least per my understanding)

I don't know if it's standard for other business types as well, like in a BV (afaik that's what you call LLC). If you're not the only shareholder, it might help prevent legal issues when you make some mistake and it just gets paid from insurance. That's the purpose of it in a stichting anyway (negligence claims; getting into debts where you could allegedly have foreseen that the foundation can't afford it)