The are not a "gatekeeper" under DMA (not enough users). Same as macOS.

Because Tesla hasn't been classified as a gate-keeper in the DMA.

> But why can Tesla ship Grok to their cars in the EU without any problems?

Simply because they are too small in user count. EU DMA, DSA etc. only apply at certain thresholds. Twitter for example falls under the scope, but Tesla is a distinct entity from Twitter and even if they were merged together, they would still be distinct services in the eye of the law.

Tesla is not marked as a gatekeeper by the EU and thus the law does not apply.