Most modern interpretations have "collapse" as only a change in the description level, not a physical process. You're right that postulates such as the project

Most modern interpretations have "collapse" as only a change in the description level, not a physical process. You're right that postulates such as the projection postulate complicate the theory. But it's not clear how to explain experimental results, like the stochastic nature of measurements or the Born rule, without it. I can make a theory as simple as you like if you don't require it to explain experimental results.