There's an epic conflict of interest here with Musk owning most of both companies. And they're in entirely separate fields, there is no plausible synergy here to be gained.

Musk has a history of having one of his more successful companies buying one of his less successful companies. xAI bought X, and Tesla bought SolarCity

Musk is notorious for shuffling assets across his companies to make some financials look better. For example, shuffling Twitter servers (and then all of Twitter) under xAI.

And hey, look at that, pure coincidence, Tesla just gave xAI $2B! Now it's back in Musk's private pockets! How handy!

lol

Musk's involvement for one.

It's just "Elon zomg lulz" trolling for updoots. This place pretends to know better.