One opened in the US city where I lived ~15-20 years ago, and they required a coin deposit to use a shopping cart. I don't cary change (not even back then), and requiring a deposit on a cart is the mark of a bad neighborhood. So I just left, and have never returned to an Aldi.
When you are comfortable approaching a stranger in a parking lot with a quarter in your hand, saying "Hey, I'll take that cart, no need for you to return it".
An even better sign is when that stranger declines to take the money and just asks you to pay it forward.
I've done both several times, in rural areas and big cities and have seen others doing the same.
Give it a try some day, it's fun.
The need to require a quarter deposit implies a lack of trust, and an "FU" to the customer. I return the "FU" by not frequenting the store.
I have been all over the United States and I have never had such an observation on carts but hey you learn something new every day.
Going back to the main point. While it might seem as a company stiffing you, it’s mainly for economic reasons at Aldis. They run on a very lean model and part of it are small things like not having employees collect carts.
I keep a couple of quarters in the car just for the Aldi shopping cart.