Shadows or rounded corners. To that I say ¿Porque no los dos?

ShadowBox.swift

extension UIView {
  
    /// Adds the subview to a container with shadows on it and returns the container.
    /// Primary use case is for a subview that clips to its bounds, and therefore can't
    /// have a shadow on its own `layer`. The shadow will match the corner radius of
    /// the contained view.
    static func shadowContainerFor(
        _ subview: UIView,
        shadowColor: UIColor? = .darkGray,
        shadowRadius: CGFloat = 2,
        shadowOffset: CGSize = CGSize(width: 0, height: 2),
        shadowOpacity: Float = 1
    ) -> UIView {
        ShadowBox(
            view: subview,
            shadowColor: shadowColor,
            shadowRadius: shadowRadius,
            shadowOffset: shadowOffset,
            shadowOpacity: shadowOpacity
        )
    }
    
    /// Adds the view to a container with shadows on it and returns the container.
    /// Primary use case is for a view that clips to its bounds, and therefore can't
    /// have a shadow on its own `layer`. The shadow will match the corner radius of
    /// the contained view.
    func inShadowBox(
        shadowColor: UIColor? = .darkGray,
        shadowRadius: CGFloat = 2,
        shadowOffset: CGSize = CGSize(width: 0, height: 2),
        shadowOpacity: Float = 1
    ) -> UIView {
        ShadowBox(
            view: self,
            shadowColor: shadowColor,
            shadowRadius: shadowRadius,
            shadowOffset: shadowOffset,
            shadowOpacity: shadowOpacity
        )
    }
    
    private class ShadowBox: UIView {
        
        private let mainView: UIView
        
        required init(
            view: UIView,
            shadowColor: UIColor?,
            shadowRadius: CGFloat,
            shadowOffset: CGSize,
            shadowOpacity: Float
        ) {
            self.containedView = view
            super.init(frame: .zero)
            addSubviewAndPinToAllSides(containedView)
            self.addShadow(
                shadowColor: shadowColor,
                shadowRadius: shadowRadius,
                shadowOffset: shadowOffset,
                shadowOpacity: shadowOpacity,
                shadowPath: UIBezierPath(
                    roundedRect: self.bounds,
                    cornerRadius: containedView.cornerRadius * shadowRadius
                ).cgPath
            )
        }
        
        override func layoutSubviews() {
            super.layoutSubviews()
            layer.shadowPath = UIBezierPath(
                roundedRect: self.bounds,
                cornerRadius: containedView.cornerRadius * layer.shadowRadius
            ).cgPath
        }
        
        required init?(coder: NSCoder) {
            fatalError(
              "init(coder:) prohibited. Please use required init "
              += "init(view:shadowColor:shadowRadius:shadowOffset:shadowOpacity:) instead."
            )
        }
        
    }
  
    private func addSubviewAndPinToAllSides(_ subview: UIView) {
        subview.translatesAutoresizingMaskIntoConstraints = false
        addSubview(subview)
        NSLayoutConstraint.activate([
            subview.topAnchor.constraint(equalTo: topAnchor),
            subview.leadingAnchor.constraint(equalTo: leadingAnchor),
            subview.trailingAnchor.constraint(equalTo: trailingAnchor),
            subview.bottomAnchor.constraint(equalTo: bottomAnchor),
        ])
        setNeedsLayout()
    }
    
    private func addShadow(
        shadowColor: UIColor? = .darkGray,
        shadowRadius: CGFloat = 2,
        shadowOffset: CGSize = CGSize(width: 0, height: 2),
        shadowOpacity: Float = 1,
        shadowPath: CGPath? = nil
    ) {
        if let shadowPath {
            layer.shadowPath = shadowPath
        }
        layer.shadowColor = shadowColor?.cgColor
        layer.shadowRadius = shadowRadius
        layer.shadowOffset = shadowOffset
        layer.shadowOpacity = shadowOpacity
        clipsToBounds = false
    }
    
}