that's only partially true at best.
chess and computers have benefited each other since the early 70s...
in case you did not know, a great grand daddy of positional play, former world champion botvinnik, in the early 70s has opened a chess school that stressed an entirely novel approach to chess at the time - computer analysis. kasparov was one of the brightest graduates of that school.
almost 2 generations of players have grown up with computers and fully utilized the advantage.
it is true, though, that modern computers are incomparably more capable, and therefore more helpful to those who prepare with them. the advantage goes only so far, since the game of chess normally is viewed - and prepared for - in terms of 3 district phases: the opening, the middle-game, and the end-game. only in the debut, the opening, a home computer preparation can be maximized. it does not mean that computer analysis has no role in the other 2 phases, quite the opposite, but it follows the law of diminishing returns the further into the game. best end-game player - and kasparov was said to be one of the best - play largely using their own intuition rather than a home prepared opening surprise...
otoh, fischer was known to stress his opening game, including stressing the most available technology att. he was ALWAYS faster than his opponents come middlegame, mostly due to his inordinate memory for previously analyzed openings.
thus, had fischer not died untimely, he would more than likely be following the best players games, including his potential opponents, through computer-aided analysis and be just as prepared if not better.
read the above qoute from nigel short who played bobby in 2001, the old man just few years before his death and after bobby has all but disappeared for 20 years. nigel, one of the best fast players in the world, was destroyed 0:8 by the old man's ever sharp weapon - impeccable openings.
so, i do not buy you coulda/woulda.