4chan is still extremely unique. It's hard for me to fully articulate but having a site that is in between a full forum and a live chat room while being anonymous CAN be great for discussion shit you're interested in without having to be caught up in individual users or people trying to judge an opinion based on the user rather than the content (not that this is perfect, with posters claiming other posters are the same person or from another thread etc). The board and topic based nature of 4chan allows basically any thing to be discussed, no matter how niche. I don't think there is anywhere else on the internet where I could discuss an old, somewhat forgotten show i'm watching like Oz (HBO), for example, multiple times a week. It doesn't have to be a discussion with a hard topic, it just creates a space where people can just talk about or give random opinions about something they're interested in and there just isn't anywhere else (in english) like that. And of course, 4chan is a place where you can literally say whatever you want and not be directly punished because you did a racism or it's the "wrong" opinion (i.e. downvotes on reddit)
Of course, 4chan has a lot of faults. Over the past decade or even longer as the site gets more and more popular and well known it's near unrecognizable in most places as it's breeded a culture of constant ragebait over the most minor, inane, or straight up made up things. Some call it shitposting but I certainly believe a lot of it is genuine. I think there's a term or phrase or something that describes the idea of when people do or say something as a joke enough, it invites people who genuinely believe in that and it really feels like that's what has ruined 4chan. The more popular a board is, the worse it is. Also, I believe 4chan has the most legitimate pyschopaths and schizophrenics of anywhere on the internet. I've been in too many threads where you have people who post the exact same image, phrase, or propaganda every day for months, sometimes years. People who go into threads about things they don't like to do nothing but try to put people down as if ragebaiting will change peoples minds. Maybe it's the anonymity of the site, i'm not entirely sure, but 4chan is a breeding ground for the mentally ill. There's also the janny/mod situation that truly came to light recently but i'll just say I personally haven't had many bad experiences with mods but it's definitely left a negative impact on certain boards like /v/ where it's very obvious jannys allow gacha, loli, and "sfw" porn threads up all day all the time despite there being other boards where that shit is supposed to go and it floods the board.
Ultimately, i'm glad the site exists and I don't think it would be good if it were to disappear. 4chan as a site only really works if it has some level of activity and that activity would be demolished if it was gone, no matter what "competitors" sprung up. I'd also like to say that i'm glad I got into KF a few years ago, I couldn't think of a way to say what I want without it sounding cringe but it's like a matured 4chan in some aspects. Effort posting is highly encouraged, pure shitposting and low effort one sentence posts are discouraged and can even get you banned. The users are still aware that the media and politics are bullshit and how so many people try to convince you trannies are beautiful and brave when they're actually just mentally ill freaks that groom kids. There aren't many places like that out there and i'm glad KF is here to control the chaos rather than breed it like 4chan.