Do I need to learn MATLAB robotics toolbox, or ROS is enough? Is there capabilities MATLAB offer that ROS can’t perform like simulation, real time control?

ROS is enough . ROS is dedicated to robotics unlike MATLAB .

MATLAB tools for visualization and simulation are poor compared to ROS, MATLAB offers tools to connect with ROS to cope with ROS progress.

ROS can connect between multiple machines easily and it is multilingual . You can code in CPP , python, java as well as arduino.

You can work seamlessly with ROS without MATLAB toolbox , but the opposite is not true.

Learn ROS first then MATLAB toolbox

And If you interested in a paid ROS course in ARABIC you can see this video and its description for enrollment