Productivity is about language + libraries + frameworks + community + your own familiarity with all of the above. The language is really the least concern when actually delivering features in a timely manner.
Programming is a high-variance activity. It's not that some programmers are 10x faster than others -- it's that an individual programmer may have 10x variance in performance on different days/weeks.
So, the two most effective things a programmer can do to become more productive are: (1) Get enough sleep. (2) Don't write code -- use libraries.
To the extent that Lisp's meta-programming support can help with (2), it's useful, but usually the lack of discoverable, minimalist, production-tested libraries is a worse tradeoff.
Essentially, the other ecosystems are good enough, and the Lisp ecosystem is not great for the bang-out-10-features-today style of most app development.
Programming is a high-variance activity. It's not that some programmers are 10x faster than others -- it's that an individual programmer may have 10x variance in performance on different days/weeks.
So, the two most effective things a programmer can do to become more productive are: (1) Get enough sleep. (2) Don't write code -- use libraries.
To the extent that Lisp's meta-programming support can help with (2), it's useful, but usually the lack of discoverable, minimalist, production-tested libraries is a worse tradeoff.
Essentially, the other ecosystems are good enough, and the Lisp ecosystem is not great for the bang-out-10-features-today style of most app development.