I'm not sure what my percentage breakdown would be.
I haven't bought anything from WoTC since (I think) sometime in 2016. So, I think that would translate into an annual D&D percentage which is low, but not quite zero. Volo's is probably the last thing I actually bought, and I think that was with a Barnes & Noble gift card. I still play D&D, but I haven't spent money on it in a long time.
In comparison, I've never bought anything related to Pathfinder 2, so that percentage actually would be zero.
I've been buying a lot of FFG Star Wars and GURPS, so -for me personally- those percentages would be high. Those are the two games I currently play most frequently. For FFG, I'm looking into picking up Genisys and a few other things, but I'm not entirely sure what the status of that game/company is at this point. For GURPS, I pick up a lot of the newer pdfs, and I'm also familiar enough with the system to pick up old books (from previous editions) and still use them.
My D&D 4E buying habits were similar to where I now find myself with 5th Edition: it's a game I play, but the game has evolved in a way which diverges from my interests, so I stop spending money on it. Surprisingly, I seem to have hit that point with 5th edition faster than I did with 4th.
During the time of D&D 3rd Edition, I bought a ridiculous amount of stuff. Though, some of the factors involved in that were being young(er) with disposable income and being new to tabletop rpgs in general -being aware of little outside of the D&D brand.
Occasionally, when I'm on the road for work, I will explore the gaming stores local to where I am. One of my primary games is a modular system, so sometimes if I see a cool monster book or something else I can convert on sale, I'll pick something up.
I bought some stuff for the 2d20 Conan game, but it seems unlikely that I will be able to play it any time soon.