Odd. I have never enabled Javascript for archive.is, especially since with it enabled they have some resource link to mail.ru and since I block .ru on my DNS it times out. The lack of requiring Javascript is the reason I use that site. I have both uBlock and NoScript blocking javascript.
To be fair, tor is a really crappy network to orchestrate a DDOS attack. On the other hand some sites just can't take much traffic, especially if it is a consistent inflow of requests. It may be that somebody just used tor as a proxy to crawl your website and it crumbled.
I happen to speculate this because I may have used tor for web crawling, which may have caused a specific site to crash before I cut back the crawl rate. Punishing tor for such incident is mostly FUD.
[1] - https://archive.is/20230504130057/https://techfreedom.org/ea...