Linux is currently mostly made by big corpo, but they are held by community and Linus’es checks.
Unfortunetly for browsers most of the giants focused on Chromium, which Google has final say over. Also Linux is OS, where browser should be simple and websites should work even if some one API is not supported. In Chromium’s world web"apps" are won’t be compatible with anything non-Chromium. Any browser would be required to support 99+% of Chromium features or not work.