Apparently the source code revealed a ton of insecurities that would make it all but impossible for them to relaunch without a major redesign, or at least that's what the actual coders that hang about here have said.
4chan has been the toilet of the internet for 22 years. They can stay down for months without it affecting anyone's loyalty. Their bigger issue has been the battle against spam making it harder and harder for normal users to post anonymously. Since they implemented the new captchas, activity went down hard and it basically killed a few smaller boards where the users were more casual and less motivated anyway.
There isn't really a place where you can post anonymously like 4chan though. Although they didn't allow VPNs since a few years so it's not totally anonymous anyway....