Since when are local-only tools not privacy focused? Being offline and local is the gold standard when it comes to privacy.
In the case of Linux, it would be for the same reason we recommend Safari on iOS, to note that switching to alternatives is not ideal.
For example, on Flathub I see WPS Office as a top recommendation for office tools with a quick search, which is closed source, has ads, and provides non-E2EE cloud document capabilities through China.
In cases other than Linux, it’s because they are available on macOS and Windows, and obviously not default on those platforms.