Like any product eventually, an arm will begin to fail and they don’t live as long as the best monitor stand options for traditional setups do. Fortunately, they’re designed well enough that your screen won’t just crash to the floor, but you’ll start to notice loosening in its movement or a loss of pressure for gas and spring arms long before an entire arm will collapse.
Generally, sealed gas and spring arms are more likely to break quicker than regular mechanical ones but provide smoother performance. Likewise, arms that are more complex with more parts are statistically more likely to fail first. There is also naturally more pressure on monitor wall mounts than desk mounts.
All that said, fortunately, unless you are overloading the arm or otherwise voiding the warranty, they are typically guaranteed from 3 to 10 years from a good brand like those on our list.
Ultimately, despite their modern vibe, arms aren’t a great feat in engineering and generally outlive the screen they hold.