Ah fair play, I didn’t realise unrar was from the same guy, cheers for the extra context.
So I guess we go back to what else it could be:
The licence could still be an issue as it’s not FOSS and parts of android are, so I guess that could prevent its inclusion if it’s incompatible with existing licences
The licence could also be an issue in terms of wanting feature parity with zip support, which would include creation of archives.
As I mentioned before, the percentage of users who are interacting with non-zip archives locally on their devices is a pretty small percentage. It may be on the backlog, but it’s not going to be far from the bottom in priority.
How many of the use cases are not served by the third party app ecosystem sufficiently that it would benefit inclusion in the actual OS and the extra maintenance that would entail
RAR is an outdated format and in decline at this point, there are better options to add before getting to it
Let’s also address the elephant in the room regarding the last point—I don’t think I’ve seen RARs used regularly outside of piracy in quite some time. If that’s the main use case, Google is not going to be bothered about supporting it.
There’s probably other reasons I’ve not thought of, but just a couple of the above are enough to explain it IMO