I don’t mean literally alphabetically but according to some objective measures. In the old days it was by incoming links (PageRank). But now it is opaque and many people are finding that it orders by whatever is best for Google, not for the user.
There is not nearly enough room on the front page for everyone that wants to be there, google has to make subjective decisions about what shows up there, it's impossible to do it any other way.
I don't think that's a bad idea, but the vast majority of google users would not desire this behavior, especially the way google is used today where users try specific terms to relocate content they have looked up before.
Yet there is no spam in the Yellow Pages. It’s very unlikely that if you call Aaron he’ll clone your credit card or install hidden cameras in your house. Also, it’s very likely that he actually is a locksmith, has the accreditation he claims to, is a legitimate business registered at Companies House, fully insured, all the things you expect of a normal business.