The post mentions the deficiencies of TCP for mobile devices over unreliable links, but I've had nothing but trouble with Wireguard when connecting from phones via mobile data.
I suspect it's due to my mobile operator doing traffic shaping / QoS that deprioritizes UDP VPN.
In contrast, connecting to OpenVPN over TCP was a huge improvement. Not at all what I expected.
Counter-anecdote: I've been using WireGuard on Android for years with no particular issues to speak of. 0.0.0.0/0 to my home network. I often forget to enable WiFi at home and don't notice (I often have it disabled when out).
I suspect ya you're right - nothing to do with Wireguard. I set it up do I could VPN into my home network from my phone. More than once, I have forgotten to turn it off. Everything worked, and I only noticed days later. Very robust, in my anecdotal experience.
The much more likely culprit is your VPN server's port. If it's running on some no-name port (such as the default 51820), that's likely to get throttled.
I'd bet that switching your VPN server port to 443 would solve the problem, since HTTP/3 runs on 443/udp.
I suspect it's due to my mobile operator doing traffic shaping / QoS that deprioritizes UDP VPN.
In contrast, connecting to OpenVPN over TCP was a huge improvement. Not at all what I expected.