I love it because I can be very specific about what I want without worrying if I forgot anything or if the person taking my order forgot it. But even more so, I'll see things that I didn't even know existed or that I could get. When all the options are right there for me to see on my own, and I have clear pricing for them, it makes the decision much easier.
Many places I call have some shitty picture of the menu on the Internet and then I have to juggle talking to them, hoping they didn't forget anything(as even saying it back is usually rushed and it's hard to make sure it got it right) or I forgot something. Add in any type of accent or language barrier and it can be a real crap shoot.
And I'm a very social person who doesn't have a problem with asserting myself. I can only imagine what it's like for people with social anxiety or are at least a bit timid.