Yeah exactly, I'd think it would need to be more than my current job because there's a lot more risk involved, such as losing the incoming revenue if the product fails. Side projects are definitely not as stable as a job is. Plus, if it's passive, why not work and do the side project to make even more money?

Yeah, completely passive income is mostly a dream for most except some extreamely lucky. I think these mostly claiming they do have passive income don't count worrying about project future, taking laptop for holidays just in case, legal risks, upfront investment or just doing tons of small housekeeping or side marketing as true activity. That especialy when passive income becomes the main one. It is optimized business.