F# has many theoretical qualities, which make it fun if you like these things, but it also has some fundamental flaws, which is why it's not getting a wide professional adoption.
- the build system was a mess last I checked (slow, peculiar)
- syntax is not c-like or python-like (a big deal for a lot of people)
- you can't hire developers who know it (and certainly the few are not cheap)
- the community is a bit weird/obsessed/evangelizing (a turn off in a professional environment)
- it's clearly a second class citizen in the .net world (when stuff breaks, good luck getting support)
On the other hand
- it has discriminated unions
- units
- etc.
but do you need this stuff (not want: need)? most people don't.