There have been almost no new broad "performance-oriented" instruction sets introduced since the Haswell era, all the way to the Zen 3 era (e.g. SIMD/vector) for compilers to target. At least not any instructions that the vast majority of software is going to see magical huge improvements from and are wide spread enough to justify it (though specific software may benefit greatly from some specific tuning; pext/pdep and AVX-512 for instance.)

The microarchitectures have improved significantly though, which does matter. For instance, Haswell-era AVX2 implementations were significantly poorer than the modern ones in, say, Tiger Lake or Zen 3. The newer ones have completely different power usage and per-core performance characteristics for AVX code; even if you could run AVX2 on older processors, it might not have actually been a good idea if the cumulative slowdowns they cause impacts the whole system (because the chips had to downclock the whole system so they wouldn't brownout). So it's not just a matter of instruction sets, but their individual performance characteristics.

And also, it is not just CPUs that have improved. If anything, the biggest improvements have been in storage devices across the stack, which now have significantly better performance and parallelism, and the bandwidth has improved too (many more PCIe lanes). I can read gigabytes a second from a single NVMe drive; millions of IOPS a second, which is vastly better than you could 7 years ago on a consumer-level budget. Modern machines do not just crunch scalar code in isolation, and neither did older ones; we could just arbitrage CPU cycles more often than we can now in an era where a lot of the performance "cliffs" have been dealt with. Isolating things to just look at how fast the CPU can retire instructions is a good metric for CPU designers, but it's a very incomplete view when viewing the system as a whole as an application developer.