In my case, it's because I'm busy at work, and the time I'd spend walking from the office to some restaurant is time that could be spent actually working.
That, and the places from which I order sometimes ain't even readily walkable in the first place unless my employer's okay with me taking a multiple-hour lunch break to walk from the office (near The Embarcadero) to, say, MAC'D (near Van Ness, so a 30+ minute walk each way even assuming I'm of at least average fitness, which I am very much not).
Re: grocery shopping, I've never done it (aside from a couple tries with Amazon Fresh), but I can understand and appreciate the time savings.
That, and the places from which I order sometimes ain't even readily walkable in the first place unless my employer's okay with me taking a multiple-hour lunch break to walk from the office (near The Embarcadero) to, say, MAC'D (near Van Ness, so a 30+ minute walk each way even assuming I'm of at least average fitness, which I am very much not).
Re: grocery shopping, I've never done it (aside from a couple tries with Amazon Fresh), but I can understand and appreciate the time savings.