Your computer may not feel faster than a 20 year old PC, but CPUs have gotten way, way faster.

Compare the AMD Ryzen 7 9800X3D to the AMD A12-9800, you go from 4 cores to 8, and you double the power consumption. But it's not twice as fast. It's 10 times faster. Depending on the exact metric, it could be as little as twice as fast or as much as 1000 times faster, depending on the exact operations.

On top of that memory throughput between DDR4 and DDR6 is about 2.5 times faster as well.

Oh and this isn't 20 years apart, this is 7 years apart. 20 years will see almost an exponentially larger gap even still.