The Terminal in macOS exposes you to the UNIX command line, something that is not in Windows. You cannot alias a Terminal command to the Desktop in macOS.
But you can place a text file on your Desktop arbitrarily named ff.command (where .command is required) with the following contents which you can edit for your -P "profileName" need in that script as you cannot pass any parameter to a .command file:
#!/bin/zsh
/Applications/Firefox.app/Contents/MacOS/firefox-bin http://www.apple.com -- 2>&1 /dev/null &
exit 0
You make this ff.command file executable, and then you just double-click it in the Finder. It will launch Firefox and quit the momentary Terminal application necessary to launch it. Any standard out and error are redirected to the bit bucket leaving Firefox running.
You can pass a parameter to an Automator application or even an AppleScript, but not a .command script since its only user input is that double-click.
Tested: macOS Sonoma 14.0 and Firefox 118.0.1.