Porto knocked us out in the Round of 16, not in the semis ffs.
A lot could have happened in the later rounds, but you definitely can't be sure that we would've won it. Porto went on to beat Lyon (who topped a group with Bayern), La Coruna (who beat defending champions Milan 4-0 in the quarters) and Monaco (who beat Real Madrid in the quarters and Chelsea in the semis, a team we were trailing in the league).
Losing to Dortmund and Leverkusen those years before sucked, but those finals against Juve and Real wouldn't have been easy too.