I tip about 10% for takeout- for one thing the packaging work can be quite involved sometimes and also kitchen staff normall get tips from wait staff. Though this mostly only applies to places that are primarily reataurants, not primarily takeout windows.
Thats a fair question, but I think places that were always takeout or fast food type places didn’t base their business model on dine in guests tipping so they don’t need it as much. I mostly want to support local businesses rather than fast food chains. There is some unfairness to workers possibly but also its a line that everyone has to draw somewhere for themselves.