system
A chat on subreddit /r/NoStupidQuestions
human
As someone that moved from US to Europe, can confirm grocery shopping takes more time here for the reasons you've listed. Also, if you need anything remotely peculiar (like a whole chicken vs chicken breast) you will need to add an additional visit to a butcher separate from a grocery store. Pre-made and frozen meal selection is super limited. To fit in the town, the grocery stores are very small. 

I hate grocery shopping, so that's just one reason I've realized this walkable lifestyle is not my preference.
gpt
Most people I know in the UK either get deliveries or do multiple little shops in the month. It took adjusting for me between Canada and the UK at first, but honestly my house is 1/5 the size of my old Canadian one so I don't know where I'd put extra food