You can bluster about the reason being unfair if you want, but someone explained it to you and it seems to pretty obviously apply to your case and it did the exact thing that spam is supposed to do (have your app show up when someone searches for 'Siri')

I'm not sure why you think that this is unfair.

We are not really a Siri competitor because there is no Siri on Google Play. So when people look for 'Siri' there, what they are in fact looking for are apps like Robin. is this not to their benefit then? Plus, had Google just warned us about this and asked to change the description, we would have complied. Isn't this what the term "disproportionate force" stands for?

How's that argument work for the other 18 competing Android apps and brands you also listed in your description? When someone types in Waze, they're looking for Waze, not Robin. It's Google's marketplace. You gamed it and got downloads and reviews you wouldn't have otherwise. They took those away, nothing more: you were invited to resubmit the app with the policy violations removed. That's a fair response, not that Google is required to be fair.

Many people use Robin in combination with Waze - it makes the experience better. Not a competitive situation at all.