As you can imagine, there are large differences between most hires for a growth marketing role (quantitative, numbers driven) and PR (media relations, focus on the pitch, relationship building, telling a story). For example, for a growth marketing role you will likely look for a numbers-driven quantitative marketer. In contrast, a communications hire will focus on storytelling, positioning, and process management.
Like all organization decisions, there’s no right answer about which executive the marketing team should report into. Making the decision is an exercise in pragmatism. In enterprise or sales-heavy companies, marketing may report into sales, product, the COO, or directly to the CEO. Marketing may be matrixed across different lines of business, or directly into each business unit. Sometimes product marketing will report into product management while PR and branding will report into another organization.
A recent trend has been to combine regulatory affairs or lobbying with PR and communications. regulatory affairs is also often found under your legal team, proving again that organizational structure is an exercise in pragmatism.
Given the code driven aspects of growth marketing, some parts of the growth marketing team may consist of engineers reporting into an engineering group versus a marketing org.
Eventually, as your company scales you might find it advantageous to have PR and branding report to a single person who may (or may not) also own product marketing and growth marketing.
Some companies have famously gone without any sort of marketing except for Growth Marketing. Wish reached an $8 billion valuation with little brand marketing or PR. The company invested very little in targeting the mainstream press, and focused instead on building momentum via growth and distribution tactics.
The takeaway is not that you should forgo a PR team (Twitter is a counter example that grew in part due to PR). Rather, each company should tailor its marketing efforts to its user base, product, and best growth vectors. In general, a high PR profile helps accelerate recruiting, deal making and partnerships, and fundraising.