> I don't want a browser to bypass DNS settings to use something else instead.
In an ideal situation, me neither. But there are a lot of users who use for example Windows 7, which will never get encrypted DNS on system level. Browsers get updates and can provide more DNS security for the average user. Not a single average user is going to configure a DNSCrypt client on their computer.
> Especially since DNS encryption and anonymization is already done on the router for the whole network.
So you would prefer using a DHCP provided DNS server on untrusted Wi-Fi networks and let it snoop on DNS queries?