@puffinkoala
Because you have to queue up for half an hour in a massive queue behind everyone else. I like Lidl coffee, but I only go once every six months to get it because I hate queuing and neither of my local ones have self-serve tills.
I have never, in my life, EVER waited half an hour in a queue in ALDI, OR LIDL. Never happened. In fact I am pretty sure that I have never waited that long in any supermarket queue!
The only time I have ever waited that long in a queue for a store, is at Currys/PC World, (who always seem to have 2 members of staff serving, and 20 members of staff wandering around aimlessly.)
And a few times I have waited in a queue for 30-45 minutes to get into a rock concert, an air show, or a Comic Con Event...
But never a supermarket, or store of any kind. (Except, as I said, Currys/PC World.)