iOS 14 PickerView cutting off text

Just add margin-left to the label would do the trick.

After the fix

Raw code:

extension UILabel {
    func setMargins(margin: CGFloat = 10, _ leftMarginOnly: Bool = true) {
            if let textString = self.text {
                let paragraphStyle = NSMutableParagraphStyle()
                paragraphStyle.firstLineHeadIndent = margin
                paragraphStyle.headIndent = margin
                if !leftMarginOnly {
                    paragraphStyle.tailIndent = -margin
                }
                let attributedString = NSMutableAttributedString(string: textString)
                attributedString.addAttribute(.paragraphStyle, value: paragraphStyle, range: NSRange(location: 0, length: attributedString.length))
                attributedText = attributedString
            }
        }
}

You can set the attributedString, as Nguyen suggested, in the ViewForRow method and edit your code like this

 func pickerView(_ pickerView: UIPickerView, viewForRow row: Int, forComponent component: Int, reusing view: UIView?) -> UIView {
    let pickerLabel = UILabel()
    let titleData = pickerDataSource[row]
    
    pickerView.subviews[1].backgroundColor = .clear
    pickerView.subviews[0].backgroundColor = .clear
    
    let myTitle = NSAttributedString(string: titleData, attributes: [NSAttributedString.Key.font:UIFont.systemFont(ofSize: 18),NSAttributedString.Key.foregroundColor:UIColor.black])
    
    let margin : CGFloat = 12.0
    let paragraphStyle = NSMutableParagraphStyle()
    paragraphStyle.firstLineHeadIndent = margin
    paragraphStyle.headIndent = margin
    myTitle.addAttribute(.paragraphStyle, value: paragraphStyle, range: NSRange(location: 0, length: myTitle.length))
    
    pickerLabel.attributedText = myTitle
    return pickerLabel
}

I'm using an even simpler label-generation method; for now my workaround is to use center alignment, as in the following example.

func pickerView(_ pickerView: UIPickerView,
                viewForRow row: Int,
                forComponent component: Int,
                reusing view: UIView?) -> UIView
{
    let pickerLabel = UILabel()
    pickerLabel.text = "Test string"
    pickerLabel.font = UIFont(name: "Ropa Sans", size: 18)
    pickerLabel.textColor = UIColor.white
    pickerLabel.textAlignment = NSTextAlignment.center
}

I wondered if this was a font-dependent defect, but since you're using the system font I conclude that it probably isn't.

A hack way is to add code below to pickerView(viewForRow:)

pickerView.subviews[0].subviews.first?.subviews.last?.clipsToBounds = false

pickerView.subviews[0].subviews.first?.subviews contains 3 view, and the last one is the real one wrapped your view, its width is smaller than the picker view, so it will trim the real content.