Since this is someone's first impression of your app, it's SO important to show a clear navigational hierarchy. Where views come from, what happens when they get dismissed, etc. When sheets slide in and out and content flashes for half a second, that mental model quickly rots.
Let's talk about the first onboarding, since this is the most widely applicable. It has you accept EULA, analytics, & grant location. It lists what location gets used for, but none are immediately useful. This should not be here — ask for permission when the user wants a feature.