A few years ago, whilst suffering with a bad case of sciatica, which went on for 3 months, i tried all the various Home Delivery Services for every UK supermarket for the first time.
My vaguely scientific experiment generated the result that, surprisingly, Morrisons was best suited for me for my 'once a month' BIG shop of heavy items, tins, everyday stuff etc for three reasons.
1. Their prices and the range of products available for home delivery were actually ok,
2. They deliver everything in plastic bags which makes it easy to transport everything from the front door to the kitchen. Yes, they charge you per bag, but you get it back when you return the bags on the next delivery (Sainsburys and Asda make you unload from their tote box on the front step, whilst the driver watches....Rubbish service for an over 70s guy)
3. For the last 4 monthly deliveries I have not had to pay for delivery at all. Morrisons keep sending me vouchers... the latest one for October is free delivery when you spend £25 online. Even when i have to pay for delivery, I usually go for one of the many £1.25 delivery slot. No brainer!
I then supplement this once-a-month big shop with weekly trips to Lidl for everything else I need, esp fruit & veg, fresh meat, fresh fish, bread, milk, yoghurts, etc and any of the weekly themed items that float my boat. I am lucky we have a massive Lidl literally less that 1-mile from my home.