What is the safest browser with built-in VPN?

Could you please elaborate on what makes a browser with a built-in VPN the safest option? Are there specific features or protocols that should be considered when evaluating the safety of such browsers? Are there any potential drawbacks or limitations to using a browser with a built-in VPN, and how can users mitigate these risks? Is there a particular browser that you would recommend as the safest option with a built-in VPN, and why?