1. High level languages (HL) are more close to English. So they are easier to learn, write and edit, understand. this is specially very beneficial when creating huge programs.
2. In HL you can write something in 100 lines. But a LL will take about 2000 lines for the same thing.
3. You can write a useful program in an hour in a HL that would take about a week in low level languages. (EX: you can write an app in Java (very high level) in an hour. But it will take weeks to achieve the same thing in a low level lang like Assembly.)
Productivity. I remember hearing about some old studies on programmer productivity, which concluded that the average programmer would produce 10 lines of good debugged product ready code per day, regardless of what language was used.
You can do more per line of code in a high level language.
Because the conversion is done by a program, which saves us from having to do it manually.
High-level programs are easier to write and easier for someone else to understand.
What is the point of cars if you have to keep wasting time by going to a gas station?
Human readibility
You are welcome to write all your programs with 1's and 0's if you prefer.
