The world could run on older hardware if software optimization was a priority

I like to point out that since ~1980, computing power has increased about 1000X.

If dynamic array bounds checking cost 5% (narrator: it is far less than that), and we turned it on everywhere, we could have computers that are just a mere 950X faster.

If you went back in time to 1980 and offered the following choice:

I'll give you a computer that runs 950X faster and doesn't have a huge class of memory safety vulnerabilities, and you can debug your programs orders of magnitude more easily, or you can have a computer that runs 1000X faster and software will be just as buggy, or worse, and debugging will be even more of a nightmare.

People would have their minds blown at 950X. You wouldn't even have to offer 1000X. But guess what we chose...

Personally I think the 1000Xers kinda ruined things for the rest of us.

I agree with the sentiment and analysis that most humans prefer short term gains over long term ones. One correction to your example, though. Dynamic bounds checking does not solve security. And we do not know of a way to solve security. So, the gains are not as crisp as you are making them seem.

You don't have to "solve" security in order to improve security hygiene by a factor of X, and thus risk of negative consequences by that same factor of X.