CATL is the biggest battery manufacturer in the world. Tesla is CATL’s biggest customer. CATL makes structural battery packs for Tesla in a plant about 3 km from Giga Shanghai. That sets the groundwork.
CATL has announced they will be offering “skateboards”. That is, a car frame, battery pack, motors and such soon. Thus, a car manufacturer can purchase “the complicated part” of a car from CATL and then add their body and interior.
It’s not that something like this has not happened before. In the past, there have been Fords built by KIA, Chevys built by Toyota and such. But, the difference here is that companies that plan to make EVs will have an efficient, proven platform to add on their touches. This will likely both improve the EV space and offer a lot more interchangability between brands.
CATL knows what they are doing and is a company big enough to do it for big car companies. This could be the next part of the EV revolution. The Electric Viking has more to say about this.