The verdict
For a small B2B team, I'd pick Webflow, because the website is usually the thing that wins or loses deals. Every B2B site I manage runs on Webflow, and I would choose it again for a modern marketing site. Pick Sellfy when you are a creator whose main need is selling files or subscriptions to an audience, and you do not want a site project. You can also use both. Embed Sellfy buy buttons on a Webflow site and let each tool do what it is good at. Webflow's own shop features are fine for small catalogues, but they are limited for large ones.