The slowest crypto that walk from grass to grace is BTC, it's the first decentralized crypto asset that works with zero hype since the Dev decided to went hidden and remain unknown to the world, BTC works with no hype at all, slowly this asset confused the world that it matters but projects of today talk and talk about thousands of promises only to end up queueing under BTC LMAO
What promise did btc said? as you've said, it's decentralized and there's no central authority that can make promises and Satoshi Nakamoto has been gone for years now.
It's slow? I don't think so, there are even much slower cryptocurrencies there and they have a higher fee. Bitcoin is good as it is right now and it's the king of the market, and that's a fact.