It is possible to add incredibly elaborate formulas into 1 spreadsheet cell. My advice: don’t. All my spreadsheet basically rely on simple +, -, *, / formulas that have 2 inputs. Each step in the calculation is clearly labeled, nicely rounded, with pretty formatting.
You can spot and trace errors easily
You can copy things easily
You can change things easily (add more inputs, years, etc.)
You can remember easily what yo did 6 weeks ago
Yes, your spreadsheets will become a lot biger, and yes, there will be a lot of repetition as you pull numbers down in new cells, instead of adding the reference directly in the formula. But it is worth it.
I see similar things happening now on the world of coding, where programmers use incredibly dense and clever code. I find it actually much harder to read and understand. And I don’t think it makes any difference to the efficiency of a program, at least when it is compiled, where the compiler strips any excess code.