If you ask questions like "Is X Pokemon worth using?", you should specify a battle format in the question itself. If you're referring to BSS Series 12, Quagsire is very much worth using. It's A rank the VR, and one of the main reasons it is used is to check Zacian Crowned. You can read about its niche here: https://www.smogon.com/dex/ss/pokemon/quagsire/bss-series-12/ .