The reason barrel adjusters with V brakes don't work well is that V brakes are long-pull brakes. This means a given pad motion requires more pull from the cable. Their cable pull is about 2.2 times as much as it is for e.g. cantilever brakes.
Thus, V-brakes require more screw threads from the barrel adjusters. Unfortunately, many barrel adjusters don't have long enough threads. For example if you use drop bar V brake levers that don't have barrel adjusters in the lever and are instead shipped with a noodle having a barrel adjuster, the barrel adjuster is not long enough. In practice you need three: one in the noodle, another after the noodle in a Jagwire Mickey adjuster, third in a Shimano SM-CB90 inline cable adjuster.
I disagree with the accepted answer claiming that actual pad wear adjustment shouldn't be made by barrel adjusters. The reason being that modern brake manufacturers are so afraid that someone could tighten a brake anchor bolt too little that they put features in the brake that crush the cable, ensuring better operation with inadequate bolt tension. However, the very same feature that allows tightening the bolt too little without danger, damages the cable after the bolt has been tightened. This means that unfortunately with these "modern" brakes you can only tighten the cable anchor bolt once. After it has been tightened, the cable has been damaged. If you need to untighten the cable anchor bolt and tighten it again, you need to throw away the inner cable and use a fresh one.
Of course this is totally stupid. Of course brake manufacturers should create brakes that don't crush the cable near the anchor bolt. However, because lawyers are today in charge and are afraid of all possible ways the products can be misused, we can't have such reasonable brakes. Thus, we need to buy brakes that damage cables when tightening anchor bolts, meaning the only reasonable way of adjusting for pad wear is barrel adjusters. In drop bar V brake systems, this means two adjusters may not be enough, you may need three of them.
Cantilever and caliper brakes don't suffer from this, since they are short pull brakes so short barrel adjusters work just fine.