Out of interest I tried applying for an ESTA today. I didn't go anything like the whole way through but then I was expecting to be told about the restrictions on entering the USA up front, but I wasn't. So then I looked around to see if I was correct and that there are still restrictions on entering the USA. It too me a while but on this page
ESTA FAQ under the heading
"Electronic System for Travel Authorization (ESTA) UpdatesElectronic System for Travel Authorization (ESTA) UpdatesElectronic System for Travel Authorization (ESTA) Updates"
I found:
"
Electronic System for Travel Authorization (ESTA) - Presidential Proclamations
9984,
9992,
9993 and
9996 temporarily suspend the entry into the United States of most individuals, other than U.S. citizens and lawful permanent residents, who were physically present in mainland China, Iran, Ireland, the United Kingdom, or the Schengen Area in the 14 days preceding their attempted entry. Any traveler with a valid ESTA who is subject to the Proclamations and who attempts to travel the United States in violation of the Proclamations will have their ESTA canceled. ESTA will not refund applications that are canceled due to the Proclamations. Travelers who have questions about whether they are subject to, or exempted from, the Proclamations should refer to the Proclamations and consult with the U.S. Department of State and the air carrier, as appropriate, in advance of travel to avoid travel disruptions. For more information, please visit the
ESTA website."
I'm going to suggest that the system allows you to apply for or modify an ESTA but then the backend checks determine you're not allowed in and they cancel the ESTA.