Arcade sticks allow you to perform advanced motions with the joystick. In addition, you can perform simultaneous button presses with ease. Different button pressing techniques open up. One technique is pianoing, which involves hitting different buttons in rapid succession to produce a certain move. In addition, instant moves can be pulled off, such as landing a normal attack right after an airdash. Finally, there exists a technique which involves hitting two buttons almost simultaneously, resulting in techniques such as kara canceling and plinking.
Using an arcade stick is also helpful when dealing with nerves, which are common during tournaments or even heated sets with friends. Besides hands getting sweaty and slippery, using sweaty hands on an arcade stick is much easier than with a regular controller. Also, it is harder to mish mash the buttons on an arcade stick when in a nervous rut due to the buttons being more spaced out than with a controller. Thus, you are automatically more aware of each press.
It is nice to be able to play at any arcade. While there might not be an arcade stick at your friend’s house, most arcade stick veterans will have likely used a controller before, and the muscle memory should still be there. However, revisiting the controller will likely feel like a setback. Fortunately, it is not that hard to bring your own arcade stick to a friend’s house.