Yes, but have you tried to optimize for code size, clarity and speed of creating features rather than just technical completeness. As a single dev there is an incredible amount of corner cutting you can do which you can polish away once the product gains traction. You can hack stuff together just as long you know how it's supposed to be properly built and how you get there from the rapid prototype.

With a team of 4 people it's very easy for no one dev to have a complete mental model, which leads to nobody truly understanding the weak points underneath.

Either you do quick hack because you want to play. Or you design nice stuff because you have to do something exceptional.

If you want passive income, you need to get out of that mentality. After work is still work, except you are the employer.