not parent either, but your still comparing a single socket of his system with a 8 core ryzen. The latter is nearly double the single thread perf, but the former has 3x the total cores when both sockets are active. Worse the benchmark is likely tilted towards newer AVX workloads/instruction sets that the older cores don't have. So for boring old integer workloads that are easily parallelized (say compiling code) its likely that xeon is at least 30% faster. Possibly more.
I'm in the same boat, I have a 12 core/64GB xeon machine I picked up 4 years ago for $200 (130W compiling). Along the way I put 4 256G SSDs on the RAID5 controller. It likely gets totally thumped by the latest 12 core ryzens, but OTOH, my compile times are ~2 minutes for a fully clean build, on that machine. A similarly spec'ed thread ripper at work only pulls that down to 90 seconds or so. Logically I can't really justify the ~$1800 the new machine is going to cost by the time I get a raided SSD, MB and 64GB ram. I might do it anyway, but its definitely not logical.
Utilizing a 24 core system is harder than an 8 core system. You will have to run multiple compiler instances which eat up memory. If you only change a single file it will take 60% longer than the newer system. Especially if you're using a single threaded linker you will be dependent on the performance of a single core. The 24 core system just doesn't perform well at all. 30% faster than a single CPU means 65% the speed of a dual socket system. Remember the original comment said that the 8 core system is "just for kids" but it's the opposite. The lower multicore performance will be compensated by the significantly higher single core performance and the upfront savings will be compensated by the fact that the newer system consumes less power.
I tend to subscribe the the fastest possible single thread mantra as well and buy low core count, high frequency machines for desktop usage. OTOH, compiled code software development is one of those areas where your better off with a few more cores vs higher frequency/newer machines. A very large number of opensource/automake/cmake/etc based projects have nearly perfect scaling out to at least a hundred threads. This is frequently true even for linker and packaging passes (given a parallel compressors like pigz). Between incremental linking, and runtime/loader linked systems (think linux kernel modules where each module is effectively a few C files linked into a .ko, each linked independently) this can even be true for the link phase as much of the overhead is IO/syscall bound even when cached.
Either way, your still missing the point, these machines cost a couple hundred dollars, and they might be a few percent slower, and 3x the power budget, but where I live that power is going to work out to $20 a year. Its going to take 50 years to make up the price difference in power, and in 5 years i'm going to buy the same machine someone paid $4k for $400 and that person is going to have to spend another $4k to get something better.
I'm in the same boat, I have a 12 core/64GB xeon machine I picked up 4 years ago for $200 (130W compiling). Along the way I put 4 256G SSDs on the RAID5 controller. It likely gets totally thumped by the latest 12 core ryzens, but OTOH, my compile times are ~2 minutes for a fully clean build, on that machine. A similarly spec'ed thread ripper at work only pulls that down to 90 seconds or so. Logically I can't really justify the ~$1800 the new machine is going to cost by the time I get a raided SSD, MB and 64GB ram. I might do it anyway, but its definitely not logical.