If you're going to create a new Lisp... you've gotta answer why it's superior to throwing a few macros on top of an existing Scheme or CL implementation.
If that were true, Scheme and CL wouldn't exist themselves. Everything you can do in those languages you could have done by writing a few macros on top of their predecessor, Maclisp.
What you seem to be saying is that the evolution of programming languages has now stopped. No one ever needs to make a new LFSP, because SPs can do whatever they need by writing macros on top of existing languages. Do you realize how unlikely this is, historically? Especially in a field like programming languages, which is at the moment in a period of ferment.
If you think CL is the last word in Lisp, you probably have a higher opinion of it than any of its designers. They were in the kitchen when it was being made, and they are all too aware of all the hacks and kludges that went into it.