Monorail equivalent to unicorn? Both have one of something, and except in short-distance shuttle or amusement park settings the former is as scarce as the latter.

All non-"duorail" fixed-guideway systems have some kind of design and/or operating issue that prevents them from cost-effectively addressing all or even a majority of use cases. All cost a fortune to build due to the all-custom-development aspects. The only ones to come close to feasibility (and might still get there, except for the need to use a lot of concrete which is becoming environmentally undesirable) are maglev and grade-separated self-driving buses.

I could see a monorail, perhaps, being used as a peoplemover around downtown LA, running in a fixed loop around downtown and connecting to Union Station. But the shuttle buses and subway(s) do a decent job of that now so why? And there are other technologies that can do the job while being easier to operate and maintain (see: Miami peoplemover, various airport technologies which sometimes include linear induction motors for tech glitz).