> without giving them founder equity
To me, it's not a question of monetary reward so much as agency. If you want me to care about something deeply, then I need to have say in how it works. I'm not going to be blindly devoted to a plan that could change at any moment for any reason.
Of course, compensation/equity matters as well, but as a programmer I tend to get heavily attached to work that matters. Nothing is more demotivating then feeling like I'm giving up free time and working long hours to build something that doesn't matter or that is poorly managed. And at a certain point, if I'm devoting that kind of energy into something, I'm going to start having opinions about it.
With many VC funded startups, workers often get sold on a vision, and then in 4-5 years they get sold to Google and everything they build dies. Workers know that their work isn't going to matter in the long run, and that the vision they're being sold could change at any moment (and in fact is highly likely to change once VCs start putting on more pressure for rapid growth). It's hard to invest emotional energy into something that fragile.
Founders have a vested interest in making sure that their baby stays under their control. But if you want me to work like a founder, treat me like a founder. And while equity is a part of that, the biggest thing is that I want a say in how that vision evolves.
The way I work on personal projects and the way I work as an employee are different. It's not the money that makes them different, it's the sense of ownership and agency. As an employee I work from a contractual "what are my obligations" perspective, because I recognize that it's not my vision, it's never going to be my vision, and that it would be problematic and against the company's interests for me to try and make it into my vision.
This is part of why I am very cautiously optimistic about the rise in popularity of worker collectives. I dislike founders who want the employee enthusiasm that comes with ownership and purpose, but none of the employee opinions and agency that are part of that.