I agree. I never use self check out. For the reasons you state, plus I don't want to contribute to some low skill person losing the only job they'll ever be able to hold.
I'm not so self-important to think that I can't stand in line at a checkout for three minutes.
Do you also litter to support low skilled people to be able to pick up your trash in service of the municipality (or whoever pays for that in the USA)?
I'm not so self-important to think that I can't stand in line at a checkout for three minutes.