Alex is right that Duda's chain passing is a problem. But a lot of BJJ chain passing, especially on the feet, is basically judo tsukuri, setting up a second attack when the first one fails. O'Toole has to defend the entry *and* the follow-up without giving up too much ground. If she's constantly reacting, Duda will wear her down.
I remember rolling with a black belt at my gym here in Kyoto, around 2018. He kept trying the same guard pass over and over. I defended it maybe eight times before he finally got it, and then he immediately swept me from the mount. It's that kind of persistence that makes Duda so good.