or, especially, software
It's a z-series mainframe and I don't doubt these reliability numbers.
The world's financial system runs on these mainframes. An undetected bit error at the federal reserve might cause IBM to appear in the news, in a bad way, like Boeing..
It will not have the fastest single-threaded performance, but that's not why you buy it.
The mainframe mindset: Of course each core is running at 100% all the time... I paid a lot for it, so I want my money's worth. z/OS is designed to make this feasible. Not sure how well that works in Linux.. but it's where the market is.