Consider this: you could, given enough time. You probably haven't had management that gave you that time. Or demanded you take the time.

Writing things down takes a lot more time than you think. It is hard work. You get better with practice.

You would find, if you were given the time, or permitted yourself to have that time, that you would find all the skills you have accumulated up to this point would converge into that plan. There is a very exciting zen you get into writing things down and you can think about the architecture and the people and the teams involved, and it's a very different thing to create. And very satisfying.

Then you'll be a senior engineer.