What makes a program load so fast?

I have this question that I need an answer to. What makes programs like st , zathura , sxiv , and feh load instantly and what makes programs like VS Code and Google Chrome load so slowly in low-spec computers? For example, I have a low-spec laptop running Linux Mint. And when I execute **st**, it instantly opens an **st** instance, but when I execute **Google Chrome**, it takes a long time to open a **Google Chrome** instance. What makes st load faster than Google Chrome and what makes Google Chrome load slower than st. Thank you! :)