Yes it's useful
yes it's nice
yes it's moral
but it's a PAIN when the fast-turnover-check-out people INSIST on bagging things (despite me begging NO I'll do it NO I'll do it PLEASE leave it to me) & they snag all the packages on the strings & crash the stuff in upside down & smashed up & I have to hasslingly rescue & repack it all myself with a fast-turnover-check-out-queue building & huffing
I have suddenly realised - they must be on commission on slithery carrier bags (5p each this week, £1,000 next), & therefore you are being punished for not being an extra subtle profit centre