Advantages: Cheaper than conventional servers, limited physical form factor suitable for constrained environments such as apartments, luggage, etc. Low power consumption, suitable for mobile/off-grid/renewable.
Recommended software: https://clusterlabs.org https://www.kernel.org/doc/html/latest/admin-guide/nfs/nfsro... https://wiki.gentoo.org/wiki/Diskless_nodes
Commercial advantage: Run highly cost and power efficient data centers, call centers, etc. Eliminate redundant state. Remove manual configuration rollout. Infrastructure as code. Full CI/CD with kernel-level control, per node, for any OS. Basically becoming a lost art in this day of "outsource to cloud". With SDN knowledge, confidently build your own cloud provider.