I take it because it's fairly cheap ($9/month), I've abused my liver and I hope it helps with that but I can't say it conclusively does. And a few companies have special phospholipidized or nanoparticalized formulas I wouldn't recommend but otherwise no one really has much to gain or lose over quercetin. It's commonly found in most fruit.
What I can personally feel is it's anti-histamine effect, so if you have allergies it's a good thing. People say it has anti-inflammatory properties but I don't feel that, at least nothing like fish oil or curcumin. And then there's a whole lot of research on it lowering blood pressure, fighting covid, killing cancer and reversing aging and while that stuff is promising (especially blood pressure) is not conclusive. It also lowers DHT in a similar way as finasteride.
It needs fat to absorb in the GI tract, so I take it on an empty stomach with fish oil. It has a synergistic effect with vitamin C, so I take a gram of extended release vitamin c with it. I also take some "citrus bioflavenoids" with it that includes hesperidan, rutin, etc. Hope this info helps