Why is brew always reporting success when failing to start a service?
Trying to debug Apache issues on any computer can be difficult, but you just have to know what commands and files to look at.  First, try to start Apache using the apachectl command and look for errors written to the screen. 

$ sudo apachectl start


If there is an error in the apache conf files or some system issue, you may see it there.   

Also, you need to review the log file and see what the service is writing about itself.  For homebrew, the log file is typically called -

/usr/local/var/log/httpd/error_log


Often, when I find that Apache won't start, it is because there is a pid lock file that makes Apache think another instance is already running and you will see this in the log file. Delete the lock file and try to start the service again.

/usr/local/var/run/httpd/httpd.pid


One final note, a great resource for using homebrew to get a LAMP environment up and running on OSX is from Andy Miller over on getgrav.org (https://getgrav.org/blog/macos-catalina-apache-multiple-php-versions). Follow those instructions and you're ready to go..