Almost every one I know in the UK has their groceries delivered. According to the official stats it’s only 7% of grocery spend though.
[1] https://www.theonion.com/no-way-to-prevent-this-says-only-na...
Most supermarkets will have a minimum spend and then there is a delivery charge on top. Both are pretty cheap but if money is tight then that is one easy convenience to go without.
... And, honestly, I'd rather buy fresh produce and perishables in person. The rest of things at the grocery store are usually cheaper in person.
Anyway, IMO, the real value of online shopping is that you no longer have those 3-hour trips from store to store to find that thing that everyone ran out of, or has poor selection. The grocery store for staples is the last thing online merchants can really replace.