Heck Peter,
There aren't even four majors. There are three championships held on changing venues, and that limited field, private party, they hold in Augusta every year, which can't hold a candle to the quality of the grand slam Bobby Jones won in 1930. Bobby set the standard for major championshps. He won on courses that changed every year against players that were not given an indefinite invitation based on having won sometime in the distant past.
Tiger Woods little party at Sherwood could qualify as a major given the standard set by the Masters.
The 4th major I would like to see is one created by the professional tours of the world. It would rotate to locations around the world on a schedule something like, Australasia; the U. S.; Canada, Mexico, South America, Africa, and the Middle East; and Europe.