For you to even think that -- especially the nonsensical "cut time in ten" claim -- means in all likelihood you don't know enough about regular JS to form a valid opinion of the frameworks. You've been spoon fed the propaganda and lies, and swallowed it hook, line, sinker, and a bit of the rod.
They do NOT save time, they do NOT make clearer code, and anyone saying they do does NOT know enough vanilla JS to form a rational choice on the topic.
I'll never understand how writing two to ten times the code, that depends on two to ten times the code you should even have, that spits out more complex and convoluted code structures, often with painfully cryptic syntax or names, all whilst slopping more on top of the underlying language to have to learn in the first place, is somehow magically "easier", "better for collaboration", "better for teams and big projects" or any of the rest of the LIES people spew about this trash.
See my other response: