In germany, paying with hard cash is still very common, having some change is basically the norm (you can also use plastic tokens instead of real coins, you can get those for free from a lot of places here, including the shop themselves, either as promotion or if you ask)
Today for the first time in two months I went to a retailer that was cash only. I haven't carried my wallet with me for two months - I just leave it at home and use Apple Pay for literally everything, including public transport.
But then, I also don't shop at Aldi or need a trolley.
Credit card fees are included in every purchase. I typically end up with 20 to 100 bucks every month. If I use that for travel I get even more. Twenty dollars in cash tends to last me an entire month.
Quite right; my family has a few plastic "coins" that work just as well.
Here in the UK, shopping carts used to take a £1 coin, which incidentally had very similar geometry to the Indian 5 rupee coin (worth about 5 pence) - that was a great little find for our family, who always had a few 5 rupee coins lying around from our time visiting family in India. Sadly they updated the design of the £1 coin, so this trick no longer works.