The business plan makes sense to me. They are a company that is focussed specifically on building AI data centers, which is a huge part of the economy at the moment. The big cloud players know about generic data centers, but there are likely big efficiency wins to be gained by specializing on AI. There is also the geopolitical angle: European countries (and others!) will likely trust a UK-based company more than one of the American BigCos. NVidia is a great partner and investor for them: NScale will buy billions worth of NVDA chips, and also send information and learnings about the unique needs of the market to the chipmaker.

That being said, financial engineering tricks like depreciation and tax sheltering are of course hugely important in the global economy. It's likely that NVDA has a lot of cash sitting in Europe that it doesn't want to repatriate because it would have to pay taxes on it.