I think what you have seen is security people saying that the design of Wireguard seems to be equal or better than other, current, options, that doesn't mean that the implementation is just yet.
It's not simply the protocol design, which is superior in pretty much every conceivable way to IKE or TLS, but also the code, which is carefully written to minimize attack surface and increase reviewability.
Choosing OpenVPN or StrongSWAN over WireGuard to minimize exposure to vulnerabilities would be a dumb bet. Sometimes dumb bets pay off, but it's still dumb to make them.
You can watch any talk about WireGuard to see what I mean about the way WireGuard's code is written, but the short answer is that the thing was designed from the bottom up to be simple. WireGuard's feature selection was influenced strongly by what would keep the codebase smaller and easier to review. It was also designed to simplify the object lifecycle inside the code itself. All its state is preallocated at initialization.
WireGuard's cryptography is essentially an instantiation of Trevor Perrin's Noise framework. It's modern and, again, simple. Every other VPN option is a mess of negotiation and handshaking and complicated state machines. WireGuard is like the Signal/Axolotl of VPNs, except it's much simpler and easier to reason about (cryptographically, in this case) than double ratchet messaging protocols.
It is basically the qmail of VPN software.
And it's ~4000 lines of code. It is plural orders of magnitude smaller than its competitors.
WireGuard isn't a panacea. In particular: clientside support for it isn't there yet! But it's pretty clear to me at least that WireGuard should imminently be replacing OpenVPN and IPSEC.
