Do you ever attain side control and then battle for ages with the same submission and end up getting nothing and having your opponent escape or reaching the end of the round with nothing? BJJ is similar to boxing in the way that you have to use your techniques in combinations instead of in isolation.
So just like boxers work combos, you can chain your submissions together. This keeps your opponent guessing and allows you to overwhelm them and get the tap.
This BJJ weekly video by renowned instructor Emily Kwok is great because Emily shows a range of far arm locks from side control chained together. She keeps things super tight and technical and explains in a clear way.