Custom PagerView to replace PageTabViewStyle, that currently has performance issues with complex views. Originally created by @mecid (https://gist.github.com/mecid/e0d4d6652ccc8b5737449a01ee8cbc6f), I've changed the animation to work just like the PageTabViewStyle when changed using `withAnimation`.

PagerView.swift

//
//  PagerView.swift
//
//  Originally Created by Majid Jabrayilov on 12/5/19.
//  Modified by Will Alexander on 10/3/2021
//  Copyright © 2019 Majid Jabrayilov. All rights reserved.
//  Copyright © 2020 appstrm. All rights reserved.
//

import SwiftUI

class PagerViewModel: ObservableObject {
    @Published var lastDrag: CGFloat = 0.0
    @Binding var currentIndex: Int
    
    init(currentIndex: Binding<Int>) {
        self._currentIndex = currentIndex
    }
}

struct PagerView<Content: View>: View {
    let pageCount: Int
    @Binding var currentIndex: Int
    let content: Content
    
    @ObservedObject var viewModel: PagerViewModel
    @GestureState private var translation: CGFloat = 0
    
    init(pageCount: Int, currentIndex: Binding<Int>, @ViewBuilder content: () -> Content) {
        self.pageCount = pageCount
        self._currentIndex = currentIndex
        self.content = content()
        
        viewModel = PagerViewModel(currentIndex: currentIndex)
    }
    
    var body: some View {
        GeometryReader { geometry in
            HStack(spacing: 0) {
                content.frame(width: geometry.size.width)
            }
            .frame(width: geometry.size.width, alignment: .leading)
            .offset(x: (-CGFloat(viewModel.currentIndex) * geometry.size.width) + viewModel.lastDrag)
            .gesture(
                DragGesture().updating($translation) { value, state, _ in
                    state = value.translation.width
                    viewModel.lastDrag = value.translation.width
                }.onEnded { value in
                    let offset = value.predictedEndTranslation.width / geometry.size.width
                    let newIndex = (CGFloat(self.currentIndex) - offset).rounded()
                    let newIndexBound = min(max(Int(newIndex), 0), self.pageCount - 1)
                    let indexToChangeTo = min(max(newIndexBound, currentIndex - 1), currentIndex + 1)
                    if indexToChangeTo != viewModel.currentIndex {
                        withAnimation(.easeOut) { viewModel.currentIndex = indexToChangeTo }
                    } else {
                        withAnimation(.easeOut) { viewModel.lastDrag = 0 }
                    }
                }
            )
        }
    }
}

#if DEBUG
struct PagerView_Previews: PreviewProvider {
    
    static var previews: some View {
        PagerViewWrapper()
    }
    
    struct PagerViewWrapper: View {
        @State var index = 0
        
        var body: some View {
            PagerView(pageCount: 4, currentIndex: $index) {
                Color.blue
                Color.red
                Color.green
                Color.yellow
            }
        }
    }
    
}
#endif

Hi, thanks for the code ! I've tried to use it inside a scrollView but I'm experiencing two issues:
1-First, when a Text with a long string inside is one of the pager components, it is automatically truncated if it has no height specified
2-If there is a LazyGrid in the content: the height of the pager is well detected inside the scrollView (which was my main issue with TabView) but the scrollview itself doesn't wan't to scroll: when scrolling down, you see the bottom of the pager view, but it springs back as soon as you end the drag gesture. As if the scrollView wasn't aware of its inner size...
I'm really not that good at GeometryReader stuff so I can't really contribute here, but I was wandering if these issues can be fixed or if I need to switch to another solution (grids are mandatory for my project)...

I can send you the project if you're interested.
Jo