"serverless means that those building applications no longer have to care about how their applications do what they do, they just have to tell the applications what to do. That’s revolutionary"
Only about as revolutionary as the concept of the subroutine: pass in arguments, get a return value, don't care how it works inside.
If you define serverless as "being able to bolt together a bunch of 3rd party applications" then this is what SOAP and Web Services APIs were promising years ago. The reality was rather different: you could end up writing a whole bunch of glue and data transformations to pull data out of X and push it into Y which ended up being more complex than the application itself. Plus there's a whole bunch of error scenarios which you need to cater for if any of the intermediate steps is temporarily unavailable or unreachable, but most people didn't bother with.
If you take serverless in its more narrow scope (such as AWS Lambda) then it just means writing code but not caring where it runs in production. Simplified operations, but essentially PaaS.