As a government cyber security person once told me "You will never know the Americans have been in your systems, you'll only know if the Russians have been, if they want you to know and you'll probably spot the Chinese but they are learning at a rapid rate and will soon surpass the Russians" that was 3 years ago.
There is a big difference between securing your IT systems against nation states and securing them against, for want of a better expression, private enterprise hacking. Realistically securing your systems against NSA intrusion is not financially viable. And that's before we even consider that your SaaS etc. are housed in readily available infrastructure in the US or touchable by the US. But that's like worrying about spy satellites taking pictures of you. A bit pointless. But so many of these "breaches" are not relying on nation state backing, basic cyber security hygiene is not observed. Your typical data breach relies on piss poor controls, so once a zero day is found and they penetrate your hard crunchy outer layer, they have relatively easy access internally, can move laterally, escalate permissions, all the good stuff we have seen for years. But with no internal controls, tripwires or monitoring, once in, they run rampant.
I have said it before and I will say it again, proper punitive punishments for Execs and boards would concentrate minds wonderfully. There are some well established frameworks out there to ensure that good hygiene is practiced. If every time a breach occurred, a forensic review by an independent 3rd party took place and if the company was found lacking, fines and prison time were on offering, you would see a remarkable reduction in these types of events.
We have the concept of fiduciary duty, a similar cyber security duty would be useful if properly implemented and with teeth.