Hey, thanks for the report. This is working as designed, not a bug.
Marketplace ranking isn’t a simple sort by downloads. There’s priority for exact matches by ID or name, for extensions from Anysphere, and for publishers with domain verification on Open VSX. Within each priority tier, results are then sorted by downloads. That’s why an extension with 3K downloads from a domain-verified publisher can rank above a more popular but unverified one.
We did this for trust and security, so verified publishers don’t get buried under lots of random extensions.
We’ve noted the feedback about ranking quality, and we’ve seen similar reports, for example Very poor extension search results. There’s no ETA for revisiting the algorithm yet.
The other extension has the name of the form namespace.go. IMO, your heuristic works very well when the extension name is more distinctive, but not in this case.