Wander00 et al
The "millennium bug" didn't affect all software but it did affect quite a lot, including operational software, with particular date formats.
There was an enormous amount of work carried out to identify which systems were at risk and then to make the necessary modifications or reimplementation to avoid the problem.
There were of course lots of bandits who jumped on the millennium bug bandwagon; some from so-called blue chip companies.
Nonetheless, the "millennium bug" was a real bug. The fact that it didn't result in disaster was because an awful lot of well meaning (or well paid) people did a lot of work to fix it.
Rgds SOS