They are both companies making EV-powered passenger cars? (And ONLY EV-powered vehicles).
Sure, but they don't sell into the same market segments.
Disagree. I was looking for a 3-row EV SUV and the only two options were a Tesla Model X and a Rivian R1S. (Maybe that's changed?)
Because articles with "Tesla" in the title get more clicks.
True. I suppose it could be considered "context" for the headline, since readers are more likely to know Tesla than Rivian, although that's also true for Ford.
How don't compete directly?
No overlapping market segments. Rivian makes an SUV, pickup, and delivery van. Tesla makes none of those.
Is the tesla model X not an SUV?
No, that's a crossover. Someone in the market for a true SUV would not consider a vehicle like that.[1]
[1]: Yes, I recognize that this looks like a No True Scotsman assertion, but there are real differences here.
Wikipedia lists both the model X and Y as "crossover SUVs", though to my sedan-buying eyes the X looks like a standard SUV and the Y doesn't. Not sure what to say. Wikipedia says SUV, my eyes say SUV.
The need for the "crossover" qualifier says it all, IMO. It's a slightly taller station wagon, not something I'm going to take 10 miles down pock-marked forest roads.