idk All of the things you're saying doesn't make Brawl worse I suppose HAVE to be a matter of opinion. Competitively I believe that the game is in fact made worse (less competitive) because:
- it's so much slower and doesn't punish the inability to think quickly
- ...it's less deep? seems obvious to me.
- there are no followups, therefore winning setup battles is more/less worthless and making mistakes goes unpunished
I also believe that this is fairly obvious: in a match between a person who can think quickly, understand nuances, and is technically good enough at the game engine to quickly attack and follow up vs a person who is awful at all these things, they are on a more/less even playing field.
That, to me, is awful and wrong.
Regarding "depth": I'm gonna bring up that terrible game I made up with the button again.
There's a button, and when it lights up, whoever presses it wins.
So I can think of ways to get better at this game. I can improve my joint health, my reaction time, add muscle, maybe bend the rules a little and shove other people out of the way. All's good and well.
Now let's add another dimension: we'll add another button to the game, so that one of the two buttons will light up and whoever presses the one that lights up wins.
That adds another skill set I have to learn; distinguishing between which button to press. Maybe I have to train both of my arms instead of just one. I have to think quickly and determine which one lights up as well, a new dimension. I can't shove people out of the way easily because they might come from another direction.
The new addition changes the skill set required to some degree, and there may be some people in the first game that aren't as good as they are in the second game.
IF several players have reached the peak of skill at the first game, then only then will the second game be more competitive. However, I don't believe anyone has ever peaked in any game.
I also think we need to redefine depth. Multiple options being "breadth," and the potential for improvement in each option as "depth."
As for thinking quickly, we can point to chess. It plays completely different in Lightning in which you have 2 minutes to make all your moves than it does in a standard game of 30 minutes. You can be better at one than the other. The speed of the game does not truly make a difference, it only calls for a different skill set.
About punishability:
I read your other post where you brought up things like Ganon's Dair leaving him at a disadvantage at low percentages, and how you can't punish mistakes.
Well, if you can't punish a mistake... it's not really a mistake, is it?

If I know that Ganon's Dair lets him get hit for free, then I can't really rely on that move at those percentages, right?
What I am trying to convey is the following:
Competitiveness only exists at extremely high levels that I don't think anyone has reached in any game. It may require a different skill set. There may be less options. But unless someone has truly reached the peak of ability, no one can't really judge this.
The only thing I can really agree with you on is randomness, tripping and the like. Things beyond our control can really change the game. In this case, I totally agree about Melee being more competitive in terms of things we can control.
About what I personally think:
-Playing Brawl makes me wish I were good at Melee during its peak, because I think it's more fun. I realized there's so many things in Melee I never learned to do.
-All the money and fame and competition, currently, is being at Brawl and not Melee.