I've been using WireGuard to replace IPsec (strongSwan - the whole stack is way too complex, plus client configuration issues, outweighs the benefits) and OpenVPN (latency, bandwidth / performance is the biggest complaint) for remote access and mainly encrypting traffic from/to terminal devices when accessing the Internet via unknown hops/routes/path.
On the other hand, WireGuard is simple (cryptokey routing), modern, elegant, easy to configure & use, fast, and most importantly, reliable over the past 2.5 years, now even better without DKMS headaches ;-)
WireGuard clients for iOS (works as good as strongSwan for Android - which I missed a while ago) in terms of 1. on-demand 2. roaming between networks 3. power consumption / overhead. macOS and Windows ones also work very well.
Problems: WireGuard does not scale well when used for global overlay network use cases (nebula does a much better job for this purpose). Another issue for VPN providers: each client has a static IP configuration, which contradicts with privacy and surveillance, curious to see how Cloudflare's 1.1.1.1 solves the problem.
Last but not least: WireGuard protocol is easy to block. Therefore, I look forward to seeing obfuscation plugins / extensions for WireGuard, it will serve a much bigger purpose for people who live under censorship/surveillance (e.g. inside GFW) so as to protect privacy and get back their rights to access the `real` Internet.
Many thanks to Jason and the WireGuard team behind the scene!