Turing Pi is mostly useful for educational purposes. For anything performance critical, a cheap 8-core x86 box will run circles around 7 Raspberry Pis in pretty much every way, no matter how they are networked.
From my perspective its 4*7 = 28 weak ARM cores vs 8 strong x86 cores. You can see that ARM actually had more cores, giving it an advantage plus to parallelized workload compared to x86.
Hell, maybe we can mix them in a bunch so that x86 runs powerful applications like GitLab, Prometheus and Postgres while ARM runs massively parallel workload that GPUs can't handle: Function as a Service (in AWS terms, Lambda; in CNCF's term, OpenFaaS), Linkerd handler (service mesh needs some kind of scheduling though), microservice replicas.
In the end CPU are all going to have a designated purposes, despite it should have had been "general purpose".