Posting on 4chan just kept becoming increasingly user hostile, especially for casual users, you had to be really determined to post something: posts started requiring 24 hour email verification, and after that you had to wait ~10 minutes before being allowed to post, and finally you had to complete a nearly impossible captcha which could lock you out from posting for an undetermined amount of time just for failing. It became apparent that the owners were pushing the gold pass pretty damn hard, and it's advertised on literally every board page.

That’s true. The captcha is impossible without the 4chan pass.

soj.ooO [1] which is similar on the other hand doesn’t have the captcha.

[1] https://soj.ooO

Not sure what this random unknown website has to do with 4chan. It's similar only insofar as both things let you post. Soj requires a sign-up so no anon posting at all, and the community structure is a pretty clear rip-off of Reddit with /p/[sub] instead of /r/[sub]

What is your affiliation with it?

https://news.ycombinator.com/threads?id=rasengan shows some previous shilling, FWIW.

> there's no other online community i know of that still allows fully anonymous posting

Doesn't 8chan/kun still exist?

> there's no other online community i know of that still allows fully anonymous posting

Usenet?

It even has the issue of old posts disappearing when the retention at your UNIX system / ISP rolled over.