When asking the question of what cubes do professional speedcubers use, it is important to consider that just because they use a certain cube does not mean that you should too. The difference between the top cubes is quite small now, especially for 3x3x3 and many top speedcubers may rely on sponsorships for income which tie them into using a specific manufacturers speedcubes. 

Nevertheless, the current 3x3x3 world record average of 4.86 (still as of March 1st 2023) is tied between Max Park, who uses the Tornado V3 and Tymon Kolasinski who uses a Gan 12 Maglev UV. Yiheng Wang who is currently ranked 3rd in the world is sponsored by Gan but it is unclear which Gan cube he uses, presumeably a gan 13. Luke Garrett used a RS3M 2022 ball core for his 5.02 average which ranks him 4th in the world.