Being able to do basic things on the command line is definitely nice. And the question is not command line VERSUS a GUI. Tower, e.g. can be used side-by-side with the command line.

However, Tower help you both become more productive and make fewer mistakes. No one likes to inspect a complex project history on the command line. Getting a visual representation of a conflict helps you resolve it more confidently. Automatically having local changes stashed away prevents problems... There are indeed many scenarios where a GUI is plain helpful - for beginners and pros alike.