VA Linux, the company behind SourceForge, bought Slashdot back in 2000, so that kinda sounds harsh to me -- I mean, the site only launched in 1997. :)
I think it slid into gradual irrelevance in the following decade, but I'm not sure there was any one moment that did it. Personally, I'd date its decline to 2011, perhaps not coincidentally shortly after founding editor Rob Malda left.
I don't honestly remember much about Beta other than not having the impression it was an improvement. :) But I don't think Dice, which bought the site in... 2012, I think?, was a very good steward of the brand.
I'd never heard of Soylent News. I can't decide if I love or hate that name. :)
I think it slid into gradual irrelevance in the following decade, but I'm not sure there was any one moment that did it. Personally, I'd date its decline to 2011, perhaps not coincidentally shortly after founding editor Rob Malda left.