cordless power tools
Each tool had their own battery, it discharged so fast and degraded even faster, and forget buying new batteries because the manufacturer decided to change the design again and either you’re stuck with a drill that only works for five minutes or buy a new one.
Now batteries last an eternity, and because each brand has their own ecosystem, as long as you buy tools from the same brand you can use the batteries you already have. And also the brands has no incentive to change the design and break the compatibility of the batteries, it would alienate the costumers who spent a lot of money on the tools and would go for another ecosystem.
Cautionary Tales
I think the description is better than what I can write.