It's Chrome dominating, Webkit a somewhat distant second [1], and Firefox a third, quickly disappearing into oblivion [2].
[1] There's a huge number of weird versions of WebKit running on TVs and such.
[2] It's barely around 200M users, but it's bleeding users slowly and surely https://data.firefox.com/dashboard/user-activity and https://news.itsfoss.com/firefox-decline/