Is 5K for this is a good amount? It seems generous to me but I’m also sure it’s only a drop in the bucket for Canva.
Having my work used in a visible way by large companies does make me wish I’d productized it more. Maybe sometime I’ll release a refactored/improved version under a different license. However, I’ve also started a company around a different open source project of mine (tldraw.com) and if there’s a bag to be got, I’m sure I’ll get it there.