10 years ago, mainstream computers were being built with i5-2500ks in them. Now, for a similar price point you might be looking at a Ryzen 5 5600x. User Benchmark puts this at a 50-60% increase in effective 1/2/4 core workloads, and a 150-160% increase in 8 core workloads.
Compared to the changes in SSDs (64GB/128GB SATA3 being mainstream then, compared to 1TB NVMe now) or GPUs (Can an HD6850 and RTX 3060 even be compared!?), it's pretty meagre!