It is a pointless number in a database collected over decades that gains nothing. Even if anyone here got 69,420 karma points, it is still point-less.
69,420 Dogecoins would still be worth more than 69,420 HN karma points or even 374,000 HN karma points.
Putting aside the overflow, if you got HN to pick three arbitrary karma milestones without communicating, they would probably coordinate on the 8bit, 16bit, and 32bit unsigned int maxes. Dang is the sole moderator for HackerNews and does amazing work in this role, so this karma milestone (while meaningless and worthless in itself) functions as a Schelling point to celebrate the effort he’s put in over the years and how much we appreciate his stewardship of the site.