Would you say this is true even if you are not interested in scaling fast and are okay with a slower "organic" growth?
(For context I have a few ideas I'd like to make a startup out of eventually, and I'm okay bootstrapping to a low/mid-volume high-niche area. I don't intend for the startup to really have massive profits, as long as I can keep it net profit and carve out a name in the niche I'll be happy.)
Unless your startup is intended to be more of a boutique consultancy and not some kind of SaaS.
If you're shopping for a high performance $10,000 oscilloscope or 3000 high endurance SD cards a month for the next 12 months, or a point-of-sales system for your small business?
Then the suppliers will have a sales person who'll visit you, demonstrate the oscilloscope's features, offer to loan it to you for a month or two so you can try it out, chase up answers to technical questions ('Can I install antivirus software on this oscilloscope?'), and suchlike.
If you're selling into an industry where that's the norm, you're probably going to need someone who knows how to do it :)