But the R0 of the coronavirus is estimated to be between 2 and 3, which is a higher infection rate than seasonal flu (1.3), but nothing like measles, which infects 12-16 new people when it spreads.

Note that even at 1.3, flu can infect millions, and coronavirus has the capability of being more infectuous than the flu. So the question is whether or not quarantine efforts succeed, not whether this has the capability to spready worldwide. It clearly does, if quarantine measures do not work.