Browser Market Share Worldwide (2009 - 2020). Source: statcounter | GlobalStats
At the very least, Chrome is worth studying. Something worked out. I’m biased, I only plan to deeply explore Chromium-based browsers and Firefox.
Stability, Testing and the Multi-Process Architecture In a single-threaded browser, devs use asynchronous APIs - which may sometimes hold the browser up. Instead of multiple threads, Chromium chose multiple processes: isolation, independent crashes, better asymptotic memory management, identifying expensive sites, etc....