for 2FA, it needs to be something that doesnt cause too much hassle to the end user, e.g. I dont want to have to unlock my phone, connect it to wifi/4g (if not already connected), load an app, and then key in some code just to login to a forum, its excessive. I would support something like a login key that's stored in my browser and sent automatically when required, akin to SSH keys. Startssl use login keys.
You don't need WiFi/4G if you setup something like Google Authenticator right. And I always use my smartwatch for that. ...Basically a second password that is stored along with cookies within your browser? I wouldn't find it as convenient myself, but whatever floats your boat. TBH, I'm thinking of switching back to texts cause I have unlimited and it would notify me whenever someone has the right password...
I know what you mean, 2FA is good for security, but in certain cases it can be annoying. For example, certain banks and brokers ask for a code for every single transaction, that's overkill to me. Plus I also don't like to use my cellphone, I rather use a hardware or software token, that's tied to a single machine.