Oh yeah, it certainly is good in cases where you have multiple team mates chasing 1 person, which is shown in all of your situations in that video
I could have worded it badly; it's useful in a single case like that, so yes it's a useful skill in woe, but limited use.
If you have group fights you simply don't have time to confine one person while there are 15 other people waiting for you to masq.
However if you have a relatively slow cast because you just started playing chaser in WoE, confining people before they speed away is nice so you have more time to masq that person. Although i would highly suggest to get fast/instant cast before playing chaser in WoE.