The risk associated with getting attacked is not large enough to warrant taking stronger security measures. Companies perform cost benefit analysis and often accept a certain amount of risk (others are just plain ignorant when it comes to security). As for a universal block, that would require a fundamental changes to the TCP / IP protocol (the internet as we know it) or for software applications to have 100% security to incoming traffic neither which seem feasible in the near future.
Disconnecting your computer from the internet would protect you granted that you do not have any malicious software currently hiding on computer. Though you may need a connection to receive security patches, fixes that may arise.
You can count me among the ignorant when it comes to security. Not so ignorant as to not comprehend what you're saying here, and I do thank you for taking the time to leave a full and credible answer to my question.
Currently I've dispensed with all malware and security programs available as I've found they're more trouble than they're worth. PUPs scare me and seem to be running around chewing up anything they can...just like any cute little puppy would. ~smiles~ I know that's not why they're called PUPs.
My security consists of updating and doing regular scans with Window's defender, and it's firewall...as well as anything added on behind the scenes by my internet service provider...which at the moment is Telus Communications. Seems to be the fix for me as I've had no problems for the past two years.
I'm sure my ignorance will come back to bite me in the bytes at some point though. Perhaps AI will come up with a universal fix. We all have enough worries away from the internet.