Yes you should practice even though your team is bowling bad or you are bowling bad. The best thing you should do in bowling is to bowl as much as you can and practice. Practicing in bowling is the best thing that you can do.
Getting better at bowling should be the thing that you should do. if your team is bad, maybe invest the team to practice so they can get better. Only practice can help you in bowling. Maybe help out your teammates when they bowl, try new things at practice or work on the things that you can’t do. Practice making share shots and what I like to do is, what happened last week league that was wrong or I bowled bad, I see what I did and try to practice on those things. If I missed 3 10 pins, then I would work on getting the 10 pin.