Here is an ESRI presentation promoting progressive web apps (PWA).
https://www.esri.com/content/dam/esrisites/en-us/about/events/media/2019-european-developers-summit/...
By definition, a PWA can work offline since the files can be cached on the user's device. And anyone with the link to the main page for the PWA will be able to open it and cache the files, including basemap tiles, on their device and do so without making any calls to ESRI's servers.
On the other hand, ESRI's TOS seems to indicate that allowing anyone to use portions of ESRI's basemaps offline as I have described is not allowed.
Can anyone shed light?
