Tea came in chests, sugar and potatoes in sacks, there'd be large jars for the shop owner to measure out from. Most things went to the shop in bulk.
Only a few were pre-packed right from the start, like bars of soap and bottles for instance. Those bottles would almost certainly have a deposit scheme. Most of the individual packaging, and variance of packaging, came with supermarkets.
It also allowed for easy adulteration of products (ever read old formulary books that were popular back then? They had a ton of "recipes" in them on how to extend or change a product to make more money from it, or sell expired goods, etc).
Imagine bulk flour sold by a company. Shop owner pays some money for it. Then reads how to "extend" the product using wood flour (aka sawdust). The shop owner reaps a much high profit, but the company that milled the flour gets a bad rep.
This kind of thing still goes on today with a variety of products that are sold to the consumer in bulk, especially where the consumer can't easy see what they are getting (or can't test it properly; for instance, it happens with gasoline occasionally).
It certainly made adulterating super easy, and in no small part led to the food safety laws both sides of the Atlantic, and the UK's trading standards. Things like alum in flour, or other equally unpleasant additives.
More recent variations on the theme have been more aware of the tendency to cheat, so have tried to make it a little more difficult. We'll always need spot checks from trading standards for restaurants and shops as someone will always try.
If laundry detergent doesn’t go bad, why aren’t I buying it in 25L or 50L barrels?
We buy 10year supplies of other products (the machines themselves), why not their consumables? They go up in price every year too.
That or buying the concentrate and diluting it yourself with the old container. That bottle of windex (spray glass cleaner) is 95% water.
Put a nice big tax on consumables, reduce the lowest rates of income tax with the revenue (or write cheques) and voila.
Instead of bigger containers, reusable containers. I have a 4 L container for laundry detergent that I fill up at the store on my walk home from work, fits nicely in my backpack.
Instead, I just buy 10x 5L containers when they’re on sale. A big waste of plastic.
Barring that, plastic foil is more friendly. Buy a refill if available.
I’m not sure if it’s just a scam to sell me liquid detergent tho.