It is hard to develop the knowledge and processes to build batteries effectively. You need to start doing it and refine your process as you learn more and expand capacity along the way. Tesla went through this phase several years ago. GM, Ford, and others are currently in this phase. They will work out the kinks. Toyota won’t learn how to do this until they actually start building batteries at scale and work out the process using the continuous improvement techniques that they learned from Deming.
Investing in electric engines is still much cheaper than investing in combustion engines.
As a reference, R&D for Mercedes' 2017+ OM654 diesel engine alone costed the company 3.5 B $. And that amount is relatively low because Mercedes had a huge know how in building diesel engines.
But in EV those amounts are much smaller, catching up is no longer a matter of decades and hundreds of billions, but years and ten times smaller investments (see Korea).
This is why China was never competitive in the ICE era, but companies like BYD are booming.
Also, I strongly believe that from now to 2035 multiple companies will be selling their electric powertrains to dozens of different automakers.
