I think marketing is a much more broader concept than most typical definitions of it portray. There's a saying by Milan Kundera that says: "business has only two functions - marketing and innovation"
Everything you do to spread the product that you've built is part of marketing. So for example when Elon Musk said that Tesla doesn't do marketing, what he really meant is that they don't do advertising. Every company markets it products, from the way you describe your products to how you scale them.
Robert Katai, an experienced marketing strategist, provides the definition of a marketing concept: “A strategy that companies and marketing agencies design and implement in order to satisfy customers' needs, maximize profits, satisfy customer needs, and beat the competitors or outperform them.” The main five include