“The uBlock Origin Lite add-on was also accused of collecting user data and running afoul of privacy concerns, which is one of the big reasons why people switch over to the Firefox browser in the first place. Hill [the developer] responded: “It takes only a few seconds for anyone who has even basic understanding of JavaScript to see the raised issues make no sense.””
On lower end smart phones? It probably just slows the phone down less specifically because of how few processes it uses in the background. But I don’t know. I’m not a lite UBO user. It definitely doesn’t have the same number of features as the regular variant of UBO though.