Much has been made about Tesla being worth more than all other automakers combined, but let's look at the growth.
Tesla Q3 Revenue: 13.76B, Year over year growth: 56%
Tesla Q3 Net Income: 1.6B, Year over year growth: 388%
GM Q3 Revenue: 26.78B, Year over year growth: -24%
GM Q3 Net Income: 2.42B, Year over year growth: -40%
Tesla is growing like bonkers, wildly more profitable, and has a much brighter future than GM given these trajectories. It's almost like either GM is severely overvalued at 90B market cap or Tesla is undervalued at 1T.
Tesla has also proven that traditional automakers really struggle to keep up with the electric car race - from software to supply chain. Rivian, like Tesla, is built top to bottom to play in this market, with the added backing of Amazon and products tailor made for enterprise scale needs that companies like Amazon need.
Of course Rivian is a risky investment today - their stock is priced for perfection. We saw what happened last quarter when stocks priced for perfection fall short (take a look at Snapchat). But plenty of these arguments "Rivian is only selling 1000 cars!" also applied to Tesla about 10 years ago.
A business is valued based on its future prospects. Growth companies are risky.
Edit to add Ford numbers:
Ford Q3 Revenue: 35.68B , Year over year growth: -4%
Ford Q3 Net income: 1.8B, Year over year growth: -23%
Also want to point out - all automakers are operating in the same pandemic - Ford, GM, and Tesla are all dealing with supply chain issues and chip shortages.