No actually, pileups aren’t just looking at a stack of rows. There are quality considerations,local realignment, multiple mapping - the data are high dimensiona

No actually, pileups aren’t just looking at a stack of rows. There are quality considerations,local realignment, multiple mapping - the data are high dimensional (genome mapping, qualities, indels) in a way that can’t be trivialized to “inspecting a stack of rows to find a defective row” The work is not trivial even if the intuition is easy