I work at a small business where probably 95% of the work gets done through spreadsheets. Spreadsheets are incredibly valuable, but yea, like you said it requires a certain mindset or discipline. Otherwise you end up with a disorganized mess which almost always has errors. The errors are bad, but the distributed arrangement of the formulas is what gets abused the most in my opinion. Modularity isn't a thing and there isn't formula re-use like in the software world. Something might be correct in one cell, but wrong in another. It could be due to bad assumptions or simply because there is so much formula repetition and the user just wasn't exercising care.