Your main concern seems to be with ongoing maintenance, but my understanding is that the "hyperscalers" like Azure don't do maintenance. They assemble everything once and then let failed components remain in-place and powered off.

Google championed this over a decade ago. They figured that the cost of staff, spare parts, diagnostics, etc... outweighed the cost of the hardware. If you factor in the complexity of liquid cooling, it might not make sense to repair hardware even a single compute node costs north of $20K.