On this page we can see an example command like this:

php application.php list --verbose=2

But as a matter of fact, it is not possible to provide a value to the --verbose option.

If you try it, the result is this exception:

[Symfony\Component\Console\Exception\RuntimeException]
The "--verbose" option does not accept a value.

To reproduce it you can run a simple command like this:
php bin/console router:match / --verbose=2

I guess this could be fixed in the InputDefinition (Symfony\Component\Console\Application::getDefaultInputDefinition method), by replacing InputOption::VALUE_NONE with InputOption::VALUE_OPTIONAL for the verbose option?