We'll never know, obviously, but had the Bulls drafted Sam Bowie instead of Michael, they would have been stuck with an injury-prone center who had a bad foot in college before he got to the NBA, which everyone including the Blazers knew about. That only got worse the more he tried to play in the NBA, because the man had a stress-fracture in his foot that never healed properly after he injured it the first time in 1981 or 1982, and this was from a movie made about big Sam's career. So his foot was simply never strong enough to play basketball, at least not basketball at the professional level.
But look at the positive aspect of this story, a team with both Michael Jordan and Clyde Drexler on it. I mean, think about it, you have Mike at the off-guard and Clyde at the wing-forward because Clyde at 6'7", 220 pounds or so, was big enough to play up front. Both were great players, both were great scorers, both were very good defenders, both could handle the ball, both could shoot, both could drive, both could rebound, etc. If you had the Blazers, with Terry Porter at point guard, and then you had found a solid center, the Blazers would have been serious NBA Finals contenders for at least 10 years.
Without Mike and with Clyde Drexler, the Blazers were NBA Finals contenders for 3 years from 1990 to 1992, and then they fell back to the middle of the pack in the Western Conference in the mid-1990s. With Sam Bowie, the Bulls would not have even been a playoff team for probably another 5 years with such an big investment in their center, who was missing half of the season or more every year. The Bulls and NBA would have been a lot different.