It occurs to me again that I need to figure out how entire websites can be downloaded and archived. Like Archive.org, but local.

Most of SPA websites today cannot be downloaded through httrack.

Yes SPAs will be next to impossible for a tool like this; I'm not sure how any tool could archive such a site tbh?

I use browsertrix-crawler[0] for crawling and it does well on JS heavy sites since it uses a real browser to request pages. Even has options to load browser profiles so you can crawl while being authenticated on sites.

[0] https://github.com/webrecorder/browsertrix-crawler