Well your VPN has a commercial interest in keeping your browsing private.
I've used self-hosted VPNs running on AWS LightSail to have privacy from wifi operators I didn't trust, but it doesn't work for higher levels of surveillance than that.
For example, if your VPN runs on a server with a dedicated or at least relatively persistent IP and you're the only one using it an upsteam of the server like an ISP or a network of sites could track you cross-site and use that data to deanonymize.