I don't think you directly answered his question; you just reiterated your opinion. I think what he's asking for is what qualities do other characters have that make them better than Olimar as a character.
I'll agree that most of the characters listed here do have exceptional damage output, but I don't think Meta Knight has that. As far as surefire combos go, Olimar tends to be good but not great. Most of his guaranteed damage come from basic "down throw to aerial" combos, but purples give them that extra oomph that similar combos don't have.
However, I think most of those characters you listed can only achieve that kind of damage output only if they're in an advantage state. Not many characters have a potentially oppressive neutral like Olimar has. Pikmin Throw is going to build up residual damage that's going to matter if the opponent doesn't react accordingly and quickly, and that process is going to accelerate with whites. Dawdle with killing the Pikmin too long, and Olimar can go in for a punishment. Ground approaches risk getting stuffed by purples or forward smashes (again, building up residual damage) or outspaced by pivot grabs, and Olimar has an advantage state solid enough to make the most out of grabs. Purples can also effectively bully the opponent out of the space that they control, forcing decisions that the Oli player can take advantage of. Played well, Olimar will force the opponent to play his game.
Olimar doesn't have the explosive advantage like Fox or Bayo has to generate a lot of damage, but he does have a really annoying neutral with lots of potential residual damage that, combined with his solid advantage state, allows to put out as much as damage as the explosive ones in a short amount of time, even exceeding them in certain situations.