But why are they doing this? What is the benefit?
If I had to guess, it’s an attempt to optimize install conversions. Every multi-step process you ask a user to perform is effectively a (marketing/sales) funnel. Some percentage of people drop off at every step. Maybe Zoom they thought that if they moved the actual installation closer to Step 1, then more people would accomplish it. It’s awfully sneaky though, especially that password dialog.