Agreed, the only argument for oil immersion cooling is, AFAIK, better energy efficiency which is of course not a real consideration for high end consumer grade hardware. A previous iteration of our national compute cluster was oil immersion cooled but the tradeoffs in maintainability etc. were not even close to sensible so the next iteration went back to regular server racks. And the iteration after that needed the floor space and finally dialed in the end of oily door handles and eerily quiet but oppressively hot server rooms.