What does it take to succeed in this dive?
Like studying anything, to succeed as a Sketch Writer, you will need to spend a lot of time... writing! The best way to get better is through consistent practice!
One thing you absolutely need is a good command of whatever language you are writing in. If you are writing in English, you need to be able to write convincing dialogue and be able to use words to help convey comedic beats properly. Same if you're writing sketches in Chinese, Arabic, or French.
Further, you need to remember these words: "Just because I don't understand it today, doesn't mean I won't understand it tomorrow." In other words, do not give up. Learning to write well in any language and at any level takes a lot of practice.
So how to succeed? Keep going. Learn constantly. Always be enrolled in a course or watch a new video or read a new book. And practice. You must actually write if you want to actually succeed at Sketch WRITING! :D
Finally, make sure you finish final drafts of your sketches, and have table reads, and even put them up live on stage or on Youtube. Yes, being a Sketch Writer is cool, but actually being a produced Sketch Writer is far more impressive.