more and more as time goes by I regret never having joined 4chan.
You don’t join it. Everyone is anonymous. You can go there today and post, but I wouldn’t recommend it.
4chan is free and anonymous you can post at any time.
That said, you may be in for quite a shock. There’s minimal moderation, so people post gore and pornographic images all the time to shock people. What would get you banned on FR (flaming, racism) is mostly permissible. In fact, most of the people on 4chan’s politically incorrect board ARE racist and anti-Semitic of varying degrees, from people who want to self segregate to full blown Stormfront, “Hitler did nothing wrong” types.
That said, it has become a somewhat of a digital smoky backroom where all kinds of people will dump intel, the trick is knowing what is real and what is people making stuff up for their own amusement.
There is no such thing as “Joining” 4chan in the sense that you do here. At the chan’s there is no account and no log in. You simply go there and read or post anonymously.