If GM doesn't do the thing you want, but Ford does, you buy the Ford.
And if there's large number of people that don't like GM and Ford, a new car company will be born and offer the thing that people want. If enough people buy it, they survive. If not enough people buy it, clearly there wasn't a large enough demand for that one feature, contrary to what people might think.
If there was only one company like Ford that is actively trying to destroy new car companies from trying to compete, that would be illegal (monopoly).
This is how it has always worked.