Actually, you see Google hiring ever more people. My colleague has worked for Google and said on multiple occasions (it is even on video) you can barely get anything done using the systems and procedures they have in place. The infrastructure/ tools for anything they have programmed there was very high maintenance and almost begins to crumble under its own weight. It is almost like an oil tanker dragging its anchor - it is still rolling, but it sure isn't a sustainable development if what you want is efficient movement forward.

That describes my employer; 15+ year old SaaS vendor.

Physical mail could easily be stolen though.

But you can still send it if you want that kind of security. There’s trade offs galore, but obviously the cheapness and convenience of email seems to have won out versus security concerns.

But its like with electoral ballots. The paper mail is hard to copy without the carrier finding out, and has to be intercepted by a local.

Email cam be copied and sent wherever without the operators knowledge, from anywhere with internet, if they break into the mail daemon.

The path of the vector of attach changes but it doesn't go away. Corp B could just bribe an overworked and underpaid mail room worker at Corp A to make some copies of sensitive looking info before they deliver it upstairs. Even today, who is to say that this doesn't happen with some overworked and underpaid sysadmins? or secretaries with their bosses email account password? I wouldn't be surprised if bribes for emails happen pretty frequently in the business world even today.

Yes, but in actual fact the chances are much bigger that that person turns out to be ethical and will report the attempted breach.

In the digital world there is no such sentry.