Google has a history of creating first-party-only APIs to give their own Android apps an edge.

In 2014 Google split their drive app into multiple separate Android apps for docs, sheets, etc. Obviously getting users to install and migrate to new apps would be a burden, so they designed a 1-click install modal that Drive could use instead of the typical redirect-to-Play-Store flow. Neat!

Around that time the company I worked for (large competitor of Drive) was about to split out some core functionality into a standalone app and wanted to use a similar flow for similar reasons - Nope! Google locked that API behind an app signature verification (not even a permission) so only Google signed apps could use it. No possibility to request the permission or appeal - just a hard-coded monopoly.

There ARE legitimate reasons that things like this can be risky and abuse needs to be mitigated, but there's a line that Google regularly crosses between abuse mitigation and anti-competitive behavior.