[wim]

Yes, this is definitely something to keep in mind. Especially when bootstrapping (what the post seems to be aimed at), building integrations with a marketplace can be a significant time investment, at the expense of working on other marketing or product improvements. Established marketplaces for popular categories are going to see diminished returns pretty quickly.

For example, we were one of the first to integrate with the Google Workspace Marketplace when it launched many years ago (called Google Apps Marketplace back then). It brought us a lot of leads in the early days. Today, discoverability has become a real problem. The "luck"-component in being featured in any search result or when browsing the marketplace is now so large that I'm not sure if for new products it would still outweigh the work of building the integration and keeping up to date with inevitable breaking API changes.

Overall it can be an amazing channel for growth though, so it's mostly about carefully picking one where customers might find you, rather than just going for something that looks promising because it's big. There's a big first-mover advantage when launching on a newish platform (and as the list proves, there's many new ones).