That's harder to do than the sentence says. And not all employers are H-1B employers. H-1B workers should be able to sponsor themselves, they shouldn't need to do the whole paperwork through businesses. So long as they can prove they meet the requirements, they should be able to apply for the visa (or its renewal).
The current system works like if every tourist had to first ask Disney to apply for their visa before coming to Orlando.
They're not tied to a particular employer, this is a myth that will seemingly never die. H1-Bs are transferrable between employers. I know multiple people in both my professional & personal life who have done so easily
Having H1-B visa employees introduce overhead. Not all companies are willing to do it. We’ve recently decided to stop H1-Bs for anyone that isn’t a senior hire.
> An eligible H-1B worker can change employers as soon as the new employer’s nonfrivolous H-1B petition is properly filed with USCIS.