Ghosting is because they don't need your work right now and are kind of dumb or ADD with bad "back office". The ones who don't ghost want onsite estimates too, because they want to size you up as a legit client, and make a sales impression. (Smooth talking white guys for the estimate, Latin Americans for the work, possibly day laborers not employees)

Small ones like leaky pipe or drywall, when the owner (or sole proprietor) is the laborer, they just come out and do on first visit.