I can’t comment on your general question, but as for the particulars of WEB…
A while back I needed a PT project to play with without any concerns of breaking it, and thought a Public Domain option would be great. Someone recommended WEB and I found the files within about 5 minutes online and needed little or no conversion to get it set up. Meaning they must have been in USFM format or something very close. So, at least in this case, you could easily create your own project of it.
[Note that in the past posts have been deleted for showing how to bypass the PT copyright restrictions, but I do not believe this is doing that. This isn’t decrypting the PT WEB resource, it’s finding a free version of it elsewhere and importing it into PT just like we do with many other projects. However, the admins can delete this if they disagree with me.]