You offer your skills as a service to other people, but I can’t imagine that your abilities to write for yourself are perfect in the eyes of every person on the planet. You have to be very picky and choosy about who you decide to work for—if anyone at all. It’s possible that your best path in the long term is not to ghostwrite for others but to build sustainable, steady income around your own writing. After all, when you take on your voice, it’s hard to argue that your ghostwritten articles are better than that.
In the meantime, though, I’m not telling you not to pursue ghostwriting, because doing so will improve your skill immensely. Your articles and writing for others has already grown in quality tenfold and will continue to do so. However, think about this grand growth in skill as part of a broader plan: to make yourself a better writer and make yourself more capable of doing your best work for your audience.