This isn't exactly correct either. It's a combination of barriers to entry (e.g. startup costs) and how much value the developer can make vs what they're paid. If a developer makes $100k/year and can create $1 million in value, then certainly I can poach them by offering them $200k/year and still make a profit on top of that.
In many fields what prevents this is startup capital. It's expensive to get a supply chain for physical goods up and running. But if you have the business acumen and connections there is not nearly as much of a barrier to entry in the software world.
You don't even need much startup capital if you're starting up not in an expensive location like SV. The reason so many of us 100kers don't up and leave when we realize we're generating millions in value is because we're only generating that value as part of a larger organism telling us what to focus on. Given individual autonomy most of us couldn't produce the same value, maybe not even our salary value. Ability to autonomously produce value seems independent from coding ability, business acumen, and connections and I would argue is far more important in building a lasting business.
In many fields what prevents this is startup capital. It's expensive to get a supply chain for physical goods up and running. But if you have the business acumen and connections there is not nearly as much of a barrier to entry in the software world.