[oshirisuki]

throughput

newer CPUs have higher levels of parallelism, therefore having higher throughput, even at the same frequency

the parallelism can be achieved via vector instructions, out of order execution, along with other changes, like better or more caching

system performance as a whole doesn't just depend on the CPU though, a beefy CPU with shitty RAM or an HDD might be worse than a mid CPU with high-speed RAM and an SSD (even a SATA one)