Different industries have different amount of willingness to endure foolishness. For at least the first 10 years, if not the first 20, any new technology is mos

Different industries have different amount of willingness to endure foolishness. For at least the first 10 years, if not the first 20, any new technology is mostly foolishness. Some technology never even makes it out of that timeframe, and just disappears before then. It takes a long time to figure out which parts of a new technology are actually useful, and which parts are just foolishness. A small SaaS startup has a relatively high tolerance for foolishness. A giant bank with billions of dollars under management has close to zero tolerance. When you say "performance/cost reasons" do you mean "just the reasons that I am familiar with and am competent to judge myself", or do you mean "all of the plethora of reasons I am clueless about, and that only an experienced actuary, accountant, or project manager from the industry has the background to judge"? I bet you're just thinking of things from your own (likely very limited) perspective. Anybody who has run even a very small business by themselves quickly finds out that a lot of the costs are hidden, subtle, and not noticed by outsiders. Can you even imagine what sorts of surprise costs are involved in running a bank?! You may think buying a cloud database from Microsoft makes total sense, and has an obvious ROI. You may also have never run a business larger than mowing your neighbors' lawns. (I don't know you. Maybe you are the CTO of an international telecom firm. Maybe I am rude to assume your background. That doesn't change my answer, though.)