Honestly given how good BigQuery is, I don't blame the sales rep for keeping their eye on their wallet. I know a lot of companies who are primarily AWS but use Google Cloud exclusively for BigQuery analysis.
(no, I'm not and have never been a Google employee)
I've used both GCP and AWS at multiple companies and personally, and my take is that a handful of important GCP products are significantly better than their AWS counterparts (Bigquery, Bigtable, Spanner, GKE), and a lot are just OK, usually slightly behind AWS in terms of features. If one of those products that's significantly better could be a differentiator for you, GCP is the better choice.
(no, I'm not and have never been a Google employee)