True “passive income” would be just buying dividend stocks. People dont like this answer because they scoff at getting a few % return a year. Then they go “well how can I make more return than that” well you can make more by putting in more effort (starting a business, etc), which by definition means its less passive 😅.
Return percentage is directly proportional to the effort you put in. Another example would be buying real estate and then hiring a management company to do all the work renting it out and maintaining it. Of course management companies are expensive and it cuts into your return so many choose again, to trade effort for return and manage it themselves. Its always a tradeoff of effort vs return.
Even if you grow a successful company and then sell it and live off the profits, you probably spent 80 hours a week for years earning those future profits - might feel passive after youve sold but definitely took effort to create that wealth.
I cant remember where I heard this advice, but what you should do is go spend a few full days sitting in a competing coffee shop thats representative of what toure tryinf to do. Write down what every person comes in and orders, and how much it costs, and add it up. Then since you already have costs from your suppliers, subtract the costs of each product and figure out roughly what the coffee shop is earning. Then cut that number in half or a quarter, and assume if you do everything well thats what you could earn.
Doing that, whats your payback period? If it takes you more than 3-5 years to earn your 300k back, its a bad idea.