There's no need for a pissing contest here. Neither the US nor the EU has a "stricter" set of vehicle safety standards than the other. They simply have
different standards.
Sometimes the differences are very minor. Sometimes it's a matter of requiring different standard equipment. Different markets around the world take different regulatory approaches in requiring active safety features versus passive safety features. Some markets focus on the safety of the occupants within the vehicle, other markets balance that safety with other road users or people outside of the vehicle. The EU tests what happens when a vehicle hits a pedestrian but the US doesn't. The US tests what happens when somebody's not wearing their seatbelt, but the EU doesn't. The EU and US crash test vehicles into different objects at different speeds and in different directions. Saying that one system is "more strict" than the other is really a gross oversimplification of the global vehicle regulatory landscape.
Heck, sometimes European manufacturers have to remove safety features from an equivalent EU-market vehicle to meet US safety standards. (e.g. Audi matrix headlights) So, just because something doesn't meet US standards doesn't mean I'm calling it bad.
Although I'm not so sure in this case... the Dacia Spring EV has a one-star Euro NCAP rating. So even the EU thinks it kind of sucks. And if you look at where it struggled, you'll see it lacked in occupant protection specifically. Which is probably not good for it being imported into the US, because US standards for occupant protection are generally more difficult to meet.
And does it really keep up with Autobahn traffic? I'm guessing it probably does fine in urban areas. But even the higher trim takes 14 seconds to get to 62mph. This is about 40% slower than the slowest car currently sold in the US. This would not be received well in the US market -- the average vehicle sold here is twice this quick. Also the top speed is 78 mph. This is slower than maximum posted highway speeds in 20% of US states. And prevailing speeds on many non-urban highways in the US are 80+.
That's not to say these are dealbreakers in usability. But nobody's gonna pay 100% tariff to import one, when you could get way better vehicle for sub ~$37,000.