It's cheaper to shop at Aldi.
It's cheaper for someone to shop at Aldi, but is it cheaper for you to shop at Aldi?
Most people never cost in their own time into any decision. If you enjoy going to Aldi or if it gives you time to bond with your kids or your partner, then great. But if you hate it, is it really cheaper. if it's a chore, then why not go somewhere better organised, where you can get everything you need, that is quicker?
Why not get your shopping delivered? Because it costs more?
Say it costs £50 to do a shop at Morrisons and £30 to do a shop at Aldi. Then say it takes an hour at Aldi because you can't find anything, you can't get everything and have to go somewhere else. This takes, say, another 1/2 hour and it only takes 20 mins at Morrisons.
You do not have to value your time very highly to get that it is cheaper not to go to Aldi.
And it should be way more obvious as time is the thing you cannot get back.