It's amusing, when you are the only one, you are # 1, when you get competition, it is hard to sustain that position.
I competed against IBM most of my career {I worked for IBM for a couple of years} and I always respected the way that they were able to stay at the top of the pack.
I made excellent money selling IBM direct competitive products {twice as nice at half the price} for short {4-6 years} periods of time, until IBM re-tooled their product or came out with a new line that just made everything else obsolete.
There are very few companies that have had IBMs success over a half century.
There is a list of also-rans longer than my patience to list them.
Think cnn, burroughs, general motors, j &l steel, ussteel, westinghouse ... and the beat goes on.
Not to mention Control Data Corp (CDC). We called IBM the itty bitty machine company but I went down with that ship in the early 80s when the PC came along and sunk the mainframes.