As to your dismissive "galaxy brains at Tesla": unlike Ford or GM or Toyota, Tesla does a lot of R&D in battery cells.

I know that because they are hiring tons of people for cell research and production: https://www.tesla.com/careers/search/?country=US&query=cell

I did similar searches in the past so I know that they've been hiring for cell research for years.

For contrast, despite GM claiming they make Ultium batteries, few months back I didn't find a single job post for cell engineering.

I also know that because Tesla has been sponsoring Canadian cell research lab led by Jeff Dahn.

This resulted in multiple patents awarded to Tesla.

Tesla also bought Grohman Engineering (which makes, among other things, robots that assemble battery packs), Maxwell (for their dry electrode technology) and a Canadian manufacturer of equipment for making battery cells.

Musk also talked how they work with every company that claims they have an improved cell technology and how they evaluate their cells.

There is no evidence that Ford or GM or Toyota made similar investments in batter cell and battery pack R&D and production.

Panasonic was crucial at the begining with their own designed\made 18650. their role is shrinking fast

Tesla's expertise when it comes to batteries is unmatched in the auto-motive industry, no doubt about that.

Tesla is not using Panasonic at all for their new batteries.