It's great to have more
It's great to have more options out there but ...
How do the solid state batteries handle cold temps (Norway cold, not southern California)?
How do they handle hot temps ( Southern Arizona not Alaska)?
What materials are used in the manufacture of them?
What is the manufacturing cost per 1000 W?
How many cycles are they currently rated for?
What vehicle are they testing them in?
Who is developing the software? Ask VW about how easy that is.
Theory is nice but not holding my breath. Case in point is a U. K. developer created efficient hydrogen powered tech, partnered with a manufacturer with the intent to release product to the public in 2019 ... since then, nada, no news, no product, no hype, nothing.
So Toyota have the hype but no real deal, and you think Toyota is going to overtake Tesla? Go ahead, put your money where your mouth is and buy Toyota stock and see if you lose your shirt or not.
Tesla is not the only pure EV manufacturer out there with viable products already out there with more to come. Toyota is well behind pure EV manufacturing ... They'll have to retool their lines and that costs $$$.