According to the BGS 2024 guide, infrastructure failure could be caused by too many wars in a short period of time.
That seems unlikely - both in the general sense, that it's really quite tricky to have a lot of wars on any individual faction in a short time because the wars themselves last quite a while, and in the specific sense that there's only been one recently in this system for the affected faction, and the IF itself didn't start for several days after that. (Other than Outbreak, none of these states have any pending time - they start immediately their conditions, whatever those are, get met)
In terms of what I've observed in general:
"Generally positive actions" => Pirate Attack or Public Holiday (higher levels of bounty hunting seem to give PH, higher trade gives PA, but it's not a definite rule)
"Biowaste transport missions / losing a war / occasionally even winning a war" => "Outbreak"
"Generally negative actions" => Terrorism, Drought, Blight, Infrastructure Failure (exactly which you get seems very difficult to predict in advance and two factions in this system have ended up in different ones; it may be to do with the type of NPC vessels destroyed but good luck testing or controlling
that)
"?????!" => Natural Disaster (it appears in the same sort of circumstances as the others - i.e. it requires a fair level of player traffic to set off - but much more rarely. It may be that its causes overlap with those of many of the other states, and those tend to trigger first)
"Contagion from Infrastructure Failure" => more Infrastructure Failure
"Contagion from Natural Disaster" => Drought or Infrastructure Failure
The causes of Outbreak and Pirate Attack, and the contagion effects, have been partly released in official Frontier documentation/videos. Everything else is guesswork.