A Virtual Private Network (VPN) can be a useful part of your online toolkit. This is especially important if you often connect to wifi hotspots when travelling away from home. In secure WiFi connections such as at shopping malls can be compromised using a ”man in the middle attack”.
If you must connect to a public network or do this often then using a VPN is a really good idea. If that is not possible then you should think about what you do while connected and avoid using mobile banking. If that is unavoidable then you could change any passwords you use when you are back at home or work and have a secure connection.
You can also disable automatic connection on your mobile devices. This means it will continue to use the cellular connection over 4G or 5G. This type of connection is less vulnerable to hacker attacks. You might still want to consider using a VPN but it is not essential and could reduce performance.
Many people are concerned about their privacy and whether their ISP is able to spy on their online activities and the information could be provided to the government. This is often cited as a reason for using a VPN at home. While that may be valid in some situations no-one should assume that what they do online is completely private.