Chips that old would be on a ~100nm process node, which is ancient. Anything using Flintstone transistors like those isn't going to hold up.
> the pentium 4 engineers probably felt like the smartest people alive
The P4's NetBurst architecture had some very serious issues, so that might not be true. NetBurst assumed that 10GHz clock speeds would soon be a thing, and some of the engineers back then might have had enough insight to guess that this approach was based on an oversimplified view of semiconductor industry trends. The design took a lot of stupid risks, such as the ridiculously long instruction pipeline, and they were always unlikely to pay off.
> the pentium 4 engineers probably felt like the smartest people alive
The P4's NetBurst architecture had some very serious issues, so that might not be true. NetBurst assumed that 10GHz clock speeds would soon be a thing, and some of the engineers back then might have had enough insight to guess that this approach was based on an oversimplified view of semiconductor industry trends. The design took a lot of stupid risks, such as the ridiculously long instruction pipeline, and they were always unlikely to pay off.