I find "painting with light" fascinating! Do you have a link to some work that you wouldn't mind sharing? I spent about 10k on a D4 and the f2.8 holy trinity a long time ago, and then another 10k on a D500, a bunch of primes and a f2.8 120-300. A fancy camera does not make one an artist! I have some pretty good shots of my 4 kids playing sports though.
Also, I am curious to know if you went mirrorless? The latest and greatest blows my mind with the speed and ISO. No way in heck I would ever upgrade though unless my glass was compatible. They knew what they were doing! My kids never played indoor sports and now I have one into basketball. It's tough to get good pics with my older gear at higher isos. I suppose I could use a flash, but I already feel like a weirdo with my 70-200 at a 4th grade game. Lol
Edit: Can you recommend software to eliminate noise?