We used to reuse code a lot. But then we got problems like diamond dependency hell. Why did we reuse code a lot? To save on labor. Now we don't have to.

So we might roll-your-own more things. But then we'll have a tremendous amount of code duplication, effectively, and bigger tech debt issues, minus the diamond dependency hell issue. It might be better this way; time will tell.

Not just to save on labour. To have confidence in a battle tested solution. To use something familiar to others. For compatibility. To exploit further development, debugging, and integration.