Made millions of dollars selling my own online courses, ebooks and a membership site using a blog and email (www.yaro.blog). Founded two service based business (BetterEdit.com - sold in 2007, InboxDone.com Co-Founder 2017), Co-Founder Pure Power (solar energy array in Ukraine), Angel investor to 12 startups, one exit so far (CarAdvice.com.au).
I went through this process with my blog, changing from Entrepreneurs-Journey.com, a 10+ year old website with plenty of domain name authority, to my own personal brand domain name - www.yaro.blog.
We did everything by the book, carefully managing the 301 redirects, telling Google about the change, and despite all this my traffic dropped by about 50% after the change.
It did eventually climb back up about 25% more, but even now over a year later it's not back to where it was.
I think the answer is be careful and make sure you are planning to work on your SEO again after you make the domain name change.