I had to give up PD after being banned a couple years ago for the same reason. I had no clue why I was banned at the time but later realized my upload speed was worthless and every hour of downloading on PD required something like 7 hours worth of uploads. Then I made matters worse when I tried to log in several months ago. For some reason I thought my account was gone, tried to setup a new account and now I'm permanently banned. That's when you tell yourself, PD is not for me.
I've used the newsgroups for years and never had a problem, but they've since changed. More and more uploads are being encrypted and password protected to the point you can't even tell what's being posted. Search engines which used to search at least the past 3 years, now only search the past year even though the newsgroup retention period is still 3 years (at least for now). I tested that theory by using old NZB files I created 2+ years ago and was still able to download the data.
One option is to post the files to the newsgroups. I understand this won't help everyone, but it could help spread the files elsewhere. I would think there are sites that have no interest in PD but would gladly download the files from the newsgroups and post them, either their own website or one belonging to a friend. They'll do that for the sole reason of increasing traffic for more Ad revenue. If that happens 3 times, it means 3 places where they can be downloaded by anyone else for free.
As far as uploading the files to the newsgroups, there are ways to lighten the load. Just as a basic example... use RAR to archive Adventure v3.1 into multiple parts... i.e. 30 parts that total 3GB. Get 3 people to post 10 parts each to the newsgroups. You could also use a 4th person to post PAR files.
Another option is to contact archive.org in order to suggest another way of getting donations. The way I understand it, their main problem at the moment is a poor download speed. Maybe they could include an option where anyone who contributes a certain amount or higher will also receive a faster download speed... based on a time period or the amount of data being downloaded. Could even assign them a password to access that faster download speed so they could choose when to use it... i.e. for certain files. Hopefully this would only be temporary and still have enough money remaining to continue supporting the site.