Even that graphic doesn't show all the companies that merged into larger companies only to be lost as a brand. GM had Pontiac and Oldsmobile which no longer exist among others. AMC was the merger of a number of auto companies and itself is no longer a brand. Same with many of the British auto makers.
Largely this is a result of the economies of scale. We like to gripe about how inefficient large companies are, but in reality size makes a company more efficient. This is very similar between auto makers and semiconductor companies. The main difference is the enormous startup costs of forming a new auto company, many billions of dollars. A semiconductor company can start with much smaller funding because the means of production can be outsourced. It's still not cheap, but it is manageable. The only successful new auto company in 50 years is Tesla which is really an EV platform company that markets their products in the form of cars. What they are really selling is motors and batteries, they just give you the car for free.