The Computer Language Benchmarks Game shows Lisp Code as generally being between 2x and 10x slower than C++[1]. As fast as C? No. Way faster than Python, and more than fast enough to be used in almost every single application, modulo hard-real-time systems and AAA video games? Yes.
> Lisp needs a lot of space to do it's thing; and while it's certainly possible to downsize it, you're left with something that's not really Lisp anymore.
Again, while a 13MB SBCL image might be significantly larger than a 100KB C program, given that that's the entire compiler and runtime bundled in, and the size of additional code scales also like C/C++, that still makes it viable for almost every kind of program (and still an order of magnitude smaller than Electron). Same deal with memory usage.
> Finding solid libraries is tricky since it's not very popular professionally.
This one is so true it's not even funny. (although there are C, C++, and Python FFI's that cover most of the stuff that you want, although that's kind of cheating)
> Unleashing the full power of Lisp in a diverse team is a recipe for an adventure, if not disaster.
The list of companies using Clojure[2], in addition to the commonly-cited Viaweb/Orbitz/Grammarly, beg to differ. Anecdotally, most Lisps have less footguns than C++ - if people can figure out how to use Stroustrup's monster in massive video games, Lisp is easy.
[1] https://benchmarksgame-team.pages.debian.net/benchmarksgame/...