It’s not even that hard to imagine, this is exactly what rogue wifi access points do. It’s surprisingly common for wifi access at places like coffee shops to be compromised and used to silently conduct these types of attacks. The people that set them up are not very knowledgeable and also they don’t ever check up on them as long as they keep working.

This is also why you want to enable HSTS on top of your HTTPS, so that rogue requests to downgrade the connection to plain HTTP are ignored.

Another good idea is to place all the services that should only be accessed over VPN only in private DNS (home LAN DNS and the VPN’s DNS), never in public DNS. A simple and effective way of doing that is to place them on a deep subdomain like *.private.example.com rather than *.example.com. That way if your VPN drops when you try to resolve those subdomains you don’t get any response anymore and there’s no connection for the rogue wifi to hijack.