Actually the environmental benefit depends on the return rate - if the van saves 5 miles on average and more than 1 in 4 return over 20 miles then it’s not helping the planet
and the impact of increased sales - everything that makes buying easier is done to drive up sales of stuff that all had a negative environmental impact - your environmental cost is proxied reasonably well by your overall spend
a loo brush can be bought as part of your weekly / monthly normal shop