It definitely works to some degree, I just think it might be better to first work your way through your "warm" network i.e. companies to which people that know and trust you or your product can make qualified introductions.
As I said I think if you can hire a professional sales team they will make it work, but that usually takes one year and costs a signficiant amount of money, so for an early stage startup it's often out of reach and very risky.
It just seems hard to believe that cold outreach won't work for SaaS