I think this is exactly what I am saying. There are companies using React that are much larger than anyone who is worried about this, and they don’t seem phased by it. That has to mean something.
Besides, isn’t the wording in this clause immediate loss of use? You’d either have to take the time to convert your app to something else before you sue them, which would still take a long time and give them the time to build/perfect your new lethal competitor, or sue them and shut your business down until you converted it to something, which is equally lethal.