What is the main disadvantage of the scripting languages as opposed to compiled programming languages?

Scripting languages are generally easier to learn than compiled languages - this is considered an advantage, not a disadvantage.

Many scripting languages, including Python, Ruby, and JavaScript, fully support object-oriented programming with classes, inheritance, and polymorphism.

Scripting languages can be used to build graphical user interfaces - for example, Python with Tkinter or PyQt, and JavaScript via Electron or browser-based frameworks.

Scripting languages such as Python, Bash, and JavaScript rely on an interpreter that reads and translates source code into machine instructions line-by-line at runtime, introducing overhead on every execution. Compiled languages such as C or C++ are fully translated into native machine code before execution, so the CPU runs instructions directly without an intermediary step. This runtime interpretation overhead is the primary and well-recognized performance disadvantage of scripting languages relative to compiled ones.