Payment was the entirety of the original purpose. As the original paper says, "a purely peer-to-peer version of electronic cash". The first sentence of the introduction starts with "Commerce on the Internet" and ends with "process electronic payments". It has failed both on "peer-to-peer" and "electronic cash". It makes no material difference to internet commerce. It has signally failed in its original purpose.
And yes, more development is always happening. Success is always in the future. Never mind that M-Pesa and Venmo and Android and Tesla all started around the same time. Uber and Lyft and Twitch and TikTok all launched years later. They all have actual success. None of them are hammers blundering around in search of a nail. None of them have to keep blowing smoke about the incredible future ahead.
But in the same way that Bitcoin is making no difference today in the real-world payment markets, none of that development is making a difference today in their equivalent markets. Colateralized loans, if they work, are 0% of the total colateralized loan market. Prediction markets have existed for more than 20 years. Adding "decentralized" doesn't make them better. Most of that "innovation" is in the category of dancing bears: the impressive part is not that the bear dances well, just that it's a bear doing the dancing.
But since you can't name a purpose, I'll just tell you: The actual current purpose of the whole circus is to enable assorted grifts. When Bitcoin got popular, that's what drove it: people seeking unearned wealth, and the people preying on the suckers with money to lose. That has kept snowballing, grift upon grift and with massive effort to create more suckers to keep the grifts going just a little longer.
Are there reasonable people caught up in this? Sure. As Madoff showed, many of the people involve on both sides of a Ponzi scheme are perfectly sincere believers. But neither their belief nor their sincerity changes the underlying truth: there is no value being created. Nobody can admit that, of course, so they just claim that the value creation is just down the road if only you hodl and believe hard enough.