It goes further than this first order, though. If you're trying to build a business that attracts the types of talent who wants to know the stack up and down, starting with an AWS instance might give you a better shot at funding (and thus a better overall shot), but it's not clear that it gives you a shot a building the business you're aiming for. For the things that "don't make your beer better", sure, but we're talking about training ML models at an ML shop. Here it makes sense for this reason.
That last part is exactly it and I while I know the intro sentence nails it I don’t think compute resonates with people (everyone uses compute). If you are 24/7 running work at scale it absolutely makes sense past the initial first couple years to build out your own DC like this.