Trees on Giessen rootstocks also produce fruit earlier, usually by the third year. Most other types take four or five years. Pollination isn't the problem it once was. Cross-pollination with another variety used to be essential, and not just any variety would do. If your orchard had just 'Bing', 'Royal Ann', and 'Lambert', you wouldn't get a single cherry because those varieties don't cross.
New varieties make cross-pollination much easier.
Well, English and Canadian scientists have developed sweet cherries that are self-fertile, just like most peaches and sour cherries. I have one of these varieties, 'Lapins', grafted on my Gisela 5 rootstock, and I see it as nearly the epitome of a backyard cherry tree. Careful management will keep the tree about 6 ft. or 7 ft. tall and about as wide, with cherry production running about 20 lb. That's plenty to keep my family regular.