The problems with ACH is that ACH takes 3 business days. If you want an "immediate" transaction, you do a wire transfer, and pay $30-60 for it, which is a hefty sum. That was one of the original "problem statements". Of course, BTC transactions are now very expensive, and that's an issue until lightning solves that.
As far as loans - the theoretical, grand idea there is that the loan market becomes global, e.g. Americans can loan to Sierra Leone, where they don't have access to a traditional, efficient banking system. Again, a pipe dream for now. Btw, there are other coins claiming to do loans based on reputation, but so far, I haven't seen them working well. And of course, there will be scammers.
As far as loans - the theoretical, grand idea there is that the loan market becomes global, e.g. Americans can loan to Sierra Leone, where they don't have access to a traditional, efficient banking system. Again, a pipe dream for now. Btw, there are other coins claiming to do loans based on reputation, but so far, I haven't seen them working well. And of course, there will be scammers.