If you're leaning towards working in the museum field, I'd recommend going down that path instead of pursuing the PhD, especially if your long-term goal isn't necessarily to stay in academia or teach. PhDs are incredibly valuable in certain contexts, particularly if you're aiming for a career in research or higher education, but they can sometimes be seen as a bit too niche or even intimidating in the broader job market.
In the museum sector, practical experience, networking, and a strong track record of hands-on work often carry more weight than academic qualifications alone. By working in the field now, you can build valuable experience, establish connections, and make a direct impact in the areas of decolonisation, inclusion, and diversity—areas that are increasingly important in the sector.
Plus, starting work sooner rather than later allows you to explore different roles within museums and find out exactly where your interests lie. You mentioned that you're not sure which area of museums you'd like to work in, so gaining experience across different roles could help you make a more informed decision about your career path.
Of course, the offer of a fully funded PhD is tempting, but unless you're passionate about research or planning to stay in academia, it might be more strategic to gain experience in the field and possibly consider further study later on, if it aligns more closely with your career goals.