What I was thinking. Less friend - more private hire driver.
There is a world of difference between a taxi which is on the go all the time and a private car which maybe has to be got out specially to do someone favour. I don't think would feel inclined to get my car out specially, to take someone on a shopping trip for £11. There is also the problem of car insurance, driving someone for hire or reward.
We have never used any of the delivery services, she walks to and from the local co-located Lidl, Tesco, Home Bargains stores or Main St local shops - all within a ten minute walk. When a big, heavy shop is needed, I get the car out.