For years all it would've taken is a solid competitor with good technology and management and Reddit is gone. Right now Reddit's really the only game in town. If someone were to come along with technology that wouldn't regularly crash and tools to help the moderators moderate and allow the community managers to quickly and effectively respond to problems; and a solid management team to be proactive and keep improving the site (not to mention make a few bucks) then Reddit would be in real trouble.
No. It was thanks to the ISPs dumping NNTP servers.
Back in the dialup days, they had NNTP servers available, pulling nearly all the NGs. As time went by, alt.binaries took over 99% of the bandwidth, along with a nice cornucopia of pirated content. It was rather awesome.
When DSL/Cable took over, those companies axed their news servers, if they had any at all. And your server choice was to use a non-binaries carrying, post limited free server or paid server.