I recently discovered that the amount of your tip paid by Doordash to delivery guys is something like:
$5 + max((customer_tip - $4), 0);
So basically, your tip benefits the driver only if it is greater than $4. Otherwise it goes into the pocket of Doordash, and its better to not tip, since Doordash marks up menu prices, and also charges an additional service fee anyway. Alternately, tip in cash, instead of tipping through Doordash.
(Okay, the above formula is not exactly correct but an approximation. Their website for dashers says:
'"For each delivery, you will always receive at least $1 from DoorDash plus 100% of the customer tip. Where that sum is less than the guaranteed amount, DoorDash will provide a pay boost to make sure you receive the guaranteed amount. Where that sum is more than the guaranteed amount, you pocket the extra amount.")
Cash tips only, every time.