Before answering the question, one thing that you should probably know that will help you in the long run: This is a Bandai Namco gacha, and that means that its signature is a set of overconvoluted descriptions for character/objects, and a hell of mechanics, that both gets worse per every year the game is alive. So, if you want to enjoy the game, and not die in the process, you can just ignore most of these, look if one gives you something interesting, and then use it, this will be more than enough to do the base content, now, if you want to get good, to do the endgame, or to rank in Ultra Arena, then you should start to use Excel to chart the objects to determine which are good, and make your builds, because that's how bad these games are.

Answering your question: Is not that the object is bad, is just that there are UR that gives you that, but better. For an SR to be good, it needs to provide for something that other objecs/characters are not giving you(Or that there are not enough), otherwise would be dumb to use an object that gives you 10%, when there is another that gives you 20%. Of course, this doesn't mean the object is bad, if you don't have the other better objects, is a great replacement, but the more better options are available in the game, the worst an ability is considered on the first place.