Stable income: Somewhat stable

Spreadsheet templates can provide a moderately stable income source for most people who try it. Based on online sources and my own experience, some individuals consistently earn from selling templates, but there can be fluctuations in income due to market demand and competition. If your best friend quit their job to do this full-time, I would say it's a risk, but potentially viable with dedication and adaptability. I'd rate it a 3 out of 5 because while there is a decent baseline for income, it may not always be predictable or guaranteed.