That strongly depends on the city and the places you park your bike. I've never needed to chain my bike, although I do it for new bikes because insurance demands it.
There are neighborhoods in cities like Amsterdam where bicycle theft is pretty much expected to happen no matter how many locks you buy, but in smaller towns there's barely a need to lock your bike at all during the day.
That strongly depends on the city and the places you park your bike. I've never needed to chain my bike, although I do it for new bikes because insurance demands it.
There are neighborhoods in cities like Amsterdam where bicycle theft is pretty much expected to happen no matter how many locks you buy, but in smaller towns there's barely a need to lock your bike at all during the day.