depends on who is doing the video and what they are unboxing. I sometimes watch those videos to decide if i want to try out a subscription box, or not bother, whether I want to buy a collector's edition of a game, or not bother with it - its basically a way for me to gauge if i want to spend money on something, or give it a pass. that said its not something I watch all the time and whatever that vid above is, its definitely not what the vids i watch look like, heck, the only time I even see the person's face is when they introduce themselves and the box at the beginning and if its pertinent to whatever they are demoing out of the box so...
edited to add, there is NOTHING wrong with taking an opinion of someone whose preferences are close to yours into account. but its not just about opinions, its also about seeing contents up close and personal. a lot of times, online listings do not give you enough information.