I think OP's main argument is that if you actually need a lot of cores, then you should probably be offloading some of that work onto a server.

I currently use a 6-core mobile H-class CPU for my work that is a mix of Java and JS development, with a bunch of browser tabs and docker containers running, large IntelliJ project, etc. While my system often has a lot of processes/threads running, the main cost of those is in memory utilization rather than constant CPU performance.

I'm not saying that can't use more CPU horsepower, but it's certainly enough for my needs (for now). The main benefit of having more cores for me right now is just to maintain system responsiveness while running a bunch of background tasks, rather than raw throughput of large compile jobs.