Unlike a stand that you have to keep on your desk, a mic boom gives you a lot more flexibility in terms of positioning your mic next to your mouth. This is especially important if you have a condenser mic that you need to have very close to your mouth for it to sound good.
At the same time, your mic arm will not only allow you to adjust the distance between your mic and your mouth optimally but also keep the microphone away from the noises of your keyboard and mouse. It might seem like a minor thing until you’ve played an intense game with your mic on your gaming desk and realize that your teammates can hear every click.
Using a mic arm, noise gate and some noise cancellation will ensure complete focus on your voice leaving out all the background noise from your recording or Discord call.
A mic arm will limit the clutter on your desk allowing for better positioning of the keyboard and mouse/mouse pad since now you no longer need to have a piece of metal between your other peripherals. This will help both aesthetically and practically since you can once again move your hands freely while playing.
The most obvious disadvantage of a mic arm is having to buy one as it is another monetary investment. If you’re on a tight budget, having to pay $30 or more isn’t entirely feasible.
One problem I’ve had myself is the adaptation period to having a piece of metal smash through your peripheral vision while you’re staring at your screen. There are people I know who could never get over the fact that they had something covering parts of their primary or secondary monitors so they either ditched the arm or used an extremely long arm to get the mic above their head (those long mics obviously cost more guns).
The final downside to a mic arm is wear and tear. A mic stand is a solid piece of metal that simply holds your microphone in place. A mic arm, however, has moving parts that need to be adjusted and locked. Over time these parts and moving parts get damaged or just break off meaning that in the long run you will need to change your mic arm at some point all in this will probably never happen with the stand of microphone included.
If you care about the quality of your sound the most and want to eliminate any background noise coming from your microphone, having a mic boom is a step in the right direction.
However, if you don’t want to spend unnecessary money and want a product that will outlast the mic itself, you should just stick with the basic mic stand. Your sound might not be the best but at least you don’t have a metal bar in your peripheral vision.