As I understand it, the .org API only provides active install data on themes: https://codex.wordpress.org/WordPress.org_API

The only source of active install data for plugins is the endpoint that was feeding their now-removed active install growth charts, and that data has been described as “wrong” and “basically garbage.” (https://wptavern.com/discussion-on-replacing-plugin-active-install-growth-data-continues-behind-closed-doors)

Unless I’ve misunderstood something, it looks like WP Rankings is based on bad data.

Other observations:
* This is purely a popularity-based ranking apart from some potential for a quality signal from ratings and support.

Daily movement +/- 20 positions out of 60,000+ — as if everyone is competing with everyone else — seems like miscontextualized and trivial stats nobody should bother with.
The “Competitors” list shown above is a strange mix of unrelated plugins.
The 10k, 20k, etc. designation of the repo were intended to add obscurity and inhibit ranking, but here they become “milestones” despite being arbitrary and based on bad data. A meaningful milestone might include major releases, higher PHP version compatibility, and time to testing with the latest WP release.

The leaderboard approach has been explicitly rejected previously, and alternative, forward-thinking was called for instead. Useful, actionable business information based on the data available is stuff like large sudden shifts in ratings, support requests, how a plugin is ranking with its tags, etc. It’s not much, but it tells plugin owners something they can actually respond to directly.