label large units in charts, source: https://stackoverflow.com/a/52602625/11472481

addUnits.R

# labels for charts
addUnits <- function(n, d = 0) {
  labels <- ifelse(n < 1000, n,  # less than thousands
                   ifelse(n < 1e6, paste0(round(n/1e3, d), 'k'),  # in thousands
                          ifelse(n < 1e9, paste0(round(n/1e6, d), 'M'),  # in millions
                                 ifelse(n < 1e12, paste0(round(n/1e9, d), 'B'), # in billions
                                        'too big!')
                          )
                   )
  )
  return(labels)
}

# you use it here
ggplot(df, 
       aes(x = x, y = y)) +
  geom_list() +
  scale_y_continuous(labels = addUnits)