No one is quite the overstatement, and I suspect it is completely wrong. Anecdotally, I and several people I know switched to Chrome when it came out due to it's blazing speed.

It would seem that was the case for many more people, see for example for a fairly old article: https://www.cnet.com/news/why-i-switched-from-firefox-to-chr...

Of course, many were using plugins with Firefox which contributed to the speed advantage of Chrome. But milliseconds matter, even program startup time.