Answer: yes and no. If you are an avid player in MMORPG games, where various actions are tied to the keys, this functionality will come in handy. As an example, you can take WoW or Lineage II. There are heaps of panels with different key combinations on the player's screen. Poking them all with the mouse is not too convenient. It is much easier to bind the necessary keyboard shortcuts to the additional mouse button.
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This also applies to working with different applications. Each program has hotkeys and commands. If the program is complex, there are many such commands. A good mouse will greatly simplify your work.
However, you have to pay for everything. The user of multi-button mice, as a rule, sacrifices practicality. The location of additional buttons, their size, backlash or informativeness can become a problem. Agree, it's a shame to lose an important match because you pressed the wrong button. When working with a mouse, it is important to intuitively understand which button you are pressing. Sometimes it comes with a habit, sometimes the inconvenience becomes eternal.
In general, before choosing a computer mouse with additional buttons, it's worth thinking about. You will have to use it every day. Therefore, you need to make sure that you are really comfortable working with the selected model.