Put simply.
Western legacy manufacturers plan for the present and build cars for a 5 year production run before changing the model, base platforms & engines for 10 years. Their profits come from spares & services not the sales of new cars. They have invested interests in the past, legacy and oil. Their debt exceeds their ability to pay the repayments so no money exists to invest
China & Tesla plan 20-30 years ahead and update their productions runs frequently to adapt to the latest technology, ways of improving reliability & reducing costs. They have no interest in the spares & servicing business as their profits come from new car sales. They have no interest in the past, legacy or oil. Investors abound, debt is small.
Many legacy manufacturers will not be here in 10 years, GM is noted as the most vulnerable.