I try not to make it more than three screens, but it's about how do you say what this does and provide the essential setup that your customer needs to be successful?
Three screens or less for mandatory onboarding
Growth → Activation & Onboarding
You have to understand that people have really limited attention and no one cares about your product the way that you do. And so it can feel like you're dumbing it down or oversimplifying. And if you don't feel that way about your onboarding, about the growth work that you're doing, it's probably too complex.
If you can think about even an online product that you're working on from that first introduction, 'What will it be like for someone to come in here? What will I be asking them to integrate with? Will I be asking them to upload something, to invite someone else? What are the steps between the user and the full value of your app?' is something that's very useful to think about literally from the first days that you're designing the product.
Unfortunately, many people think about onboarding at the last minute and it ends up being the final piece of product work, or, and this may be a little bit controversial of an opinion, but I'm not a fan of the plug and play frameworks for onboarding for that reason.