If you're trading in small amounts, the comissions add up pretty quickly, a $10 comission on a $1000 purchase of stock ends up being 2% of the price, considering you have to pay to buy and to sell. That's way better than a $30 comission from the before times, but it's still big.
That said, we can all thank RobinHood for driving comissions down to zero, and then do business at brokerages that work. I personally wouldn't trade at IB, because I only do a tiny amount of trading, and don't want to go into the rabbit hole of individually routing my orders; it's great that it's available, but I don't need that, nor do I want an API or stuff.