This is not an option for home DIY builders, unless they have more money than sense
I wouldn't necessarily disagree with that, given the cost of a complete system on this platform. I was also a professional software developer, now retired. The last system I built for myself around 2013, which I'm still using, is a dual AMD Opteron 4234 with 16 GB of memory and all SSD storage. If I were to build a new system today, it would be with Threadripper. Though as I mentioned, for software development 8 memory channels is overkill; 4 really was the sweet spot. I ran our complete runtime environment on my system: a DBMS (Oracle or PostgreSQL), a web server with a JavaEE stack, a JBoss app server, plus all my development tools (Eclipse, etc.)
So, there is still a need for powerful workstation-class systems for individual end-users, but the numbers are small compared to the overall size of the market.