Your VPS has an ip. All your traffil will go through it if you set it up as a VPN. So your behaviour patterns will be tied to that one IP. You will be the only one on that VPN.
A commercial VPN has many users at the same time on a given Server. So the traffic and behaviour that comes from that servers IP will produce garbage data for analysis.
You could selfhost a VPN on your VPS and let others use it for free somehow to obfuscate your behaviour and patterns, but you as the VPS owner will have to deal with legal stuff then.