Google is not a source; what exactly are you seeing that suggests that? The only things I can find against wg are that 1. it hardcodes crypto options, so if ex. its cipher choices proved vulnerable then it would be harder to fix (vs openvpn allowing, more or less, plug and play of whatever cipher you want), and 2. openvpn has been around longer. But wg is much less code to audit, has been audited, is now widely deployed and used at scale, and hardcodes extremely safe cryptographic choices. So... again, what specific claims/sources say that openvpn is safer?
Wireguard is written by Jason Donenfield, a renowned developer with deep crypto knowledge. You can search him up and see for yourself. https://www.zx2c4.com/
