Reddit began in a similar way - being very tech focused until it started to become much more mainstream.
I wasn’t at the beginning of Reddit, but I have been a user since 2013 and I always was confined in my little bubble of interests (I used it as a replacement of Feedly, so I pretty much created my curated content) it was not until the APIcalypse that it was mentioned over and over that r/all wasn’t even that good nowadays, and I was like, bruh, I should go there often, I did, and still do, but I still browse my curated content, whether is here or Reddit.