I beg to differ. I’m fairly sure I’ve heard about meltdown on modern CPUs.
Are you really sure they aren’t snowflakes?

Pentium I came with flimsy passive cooling.
From Pentium II on or AMD K6-2 active cooling was the norm.
486 typically went without cooling.

I once installed Windows on a Pentium 3 without cooler - not on purpose though - and it worked!
Well, installing the OS was on purpose, the CPU being without cooler not so much.
Apparently modern CPUs are snow flakes 🤓