Is tunnel VPN safe?

I've been hearing a lot about tunnel VPNs recently, and I'm curious about their safety. Could you please enlighten me on this matter? I've read some conflicting opinions on the internet, with some people claiming that tunnel VPNs are perfectly secure, while others warn about potential risks. So, what's the truth? Are tunnel VPNs safe to use, or should I be cautious? Could you explain the underlying security mechanisms and any potential vulnerabilities I should be aware of? I'd really appreciate your insights into this topic. Thank you!