SEO isn't about driving traffic. It's about optimizing your site to work best with search engines. Driving traffic is done through marketing, outreach, and advertising.

I think the problem you're having on this discussion is that there is no set in stone definition of SEO.

Some people consider driving traffic to your site to be a part of SEO, you don't.

I think they both are right, just focusing on different parts of SEO. Ranking higher produces more traffic. That can be achieved mainly through on page SEO and, he calls it outreach and marketing, others call it link building.

The confusion therefore is caused by the use of different terminology.