VPN usage is absolutely legal, since it is just a technology to connect different IP networks. It enables encryption and secure transport of the data. Also it is widely used by companies to merge their office branches into a single network.
Consider VPN as a kitchen knife. Use it, sell it and buy kitchen knifes are absolutely legal, but killing people with this tool is not. So using VPN for legit activities is legal, another question what is a legit activity?
Personal VPN providers, such as Seed4.Me, allow people to change their jurisdiction virtually and avoid charges in the country of their origin. If “virtual change of jurisdiction” is considered as illegal activity, then it is illegal.
But most of the countries do not have any regulations regarding “jurisdiction change”, so it’s perfectly legal to use VPN.