Stellantis has an advantage of making cars around the world. So they can offer cars and have in house design and manufacturing people for them. GM and Ford, not so much. Car engineers and designers likely moved to other companies or are aging as new people choose car companies.
https://www.briggsdodge.net/blog/which-vehicles-does-stellantis-make/amp/
https://www.briggsdodge.net/blog/which-vehicles-does-stellantis-make/amp/
