How VPNs can make web browsing safer

Yesterday I was thinking about how much personal stuff people handle through a normal browser now. I check bank pages, work documents, shopping accounts, email, and even medical appointments online, often without thinking about whether the connection is really safe. A few months ago I used public Wi-Fi at a mall and later got a strange login alert, which made me more careful. Since then I’ve been reading about VPNs, and I found this page about VPN for android helpful. Do you think a VPN is useful for everyday web browsing, or only when someone uses public networks?