And then US government prints trillions of dollars and inflate your savings. Or Russian government locks you USDs while Visa, Mastercard and sanctions make it impossible to move money out of the country. Or ask Belorussians and Argentinians how much they like double digit inflation that goes year after year after year while government limits ability to buy a more stable currency.

Above is just about money but there is another perspective. Think about a car sale and how would you automate it. To date most car sales require some paperwork to register the right transfer. This happens behind the scenes and you may not know but it happens and occupies some people. You simply cannot automate a car same with just a database. There must be a trust component in the system and a way to maintain it. Trust maintenance typically means audits, licensees, etc and they do not come for free.

XRP is special in that it's distributed, but I wouldn't call it decentralized (so you're completely correct in calling it a crypto with a centralized authority). For instance it's possible for nodes to block other nodes at their whim. This is a very attractive trait for banks or groups of banks. But similarly it's a very bad trait for any smaller actor. So sure, it works, but it also gives up huge amounts of control to central authorities. I mean, if you're OK with giving up your freedom to uncontrollable inflation, then go right ahead and use it!