Well, they are already coming. Recently, Tesla went from being #1 for a long time to #7 for EV sales in Norway (7 Fully Electric Vehicles In Norway's Top 10). They barely sold more than BMW i3, and got outsold by the LEAF almost 2:1. The top vehicle was the Audi eTron which outsold the Model 3 more than 4:1.
Similar fate likely awaits in other countries once the rest of the EV lineups arrive there. A lot more EV's are coming in the next 2 years, even if half of them don't make it, Tesla will still be facing stiff competition.
Major difference between Norway and the US is the availability of third party fast charging options. Competition is coming but I have yet to see decent products apart from Rivian.