Personally my 2.6b tier list was along the lines of like...
1. Fox
2. Falco
3. Sheik
4. Peach
5. Metaknight
6. Wolf
7. Mario
8. Captain Falcon
9. Ivysaur
10. Zelda
11. Pit
Pit was still better than most of the rest of the cast, and did just fine vs Metaknight, Mario, Ivysaur, and Zelda. He lost to 6/10 of the top tier character, and had mostly advantageous match ups vs the rest of the cast. Examining the cast more in-depth, Pit actually is still a fairly solid character, but he still falls in to the top of mid tier. If we compared Pit to a character in Melee, it would be Doc. He is notably better than the rest of the cast, and has a few decent match ups in the top tiers, but character experience invalidates a lot of what Pit can do. If a Pit is winning on screen we can assume that at least one of two things is true.
A. The Pit is the better player.
B. Pit's opponent does not know the Pit match up.
In many cases based on videos posted, and tournament results, it was B more often than A. In my case, players notably worse than me overall have actually taken sets off me in tournament because they just knew the Pit match up well enough. Switching to a different character yielded the expected result of me winning. Some of Pit's match ups are also so bad that for example:
Though Silly Kyle, and DJ Nintendo are better players than me, we're of comparable skill level. You would expect close 1 and 2 stock matches. What ACTUALLY happens DJN, and Kyle, with no Pit experience, both demolished my Pit, because the Fox and Peach match ups are just THAT heavily skewed in their favor, which further brings down my opinion of Pit. Hard counters in the top tier made Pit's overall tournament viability of a character that much worse in pre-3.0.
ZSS lost to any character that can do good character things, her whip clanks with thinks, and her fully charged stun gun gets clanked with a lot of common moves.
Lucas had a highly exploitable recovery, and approach. Any character that can camp 45 degrees above him.
Bowser lost to any character with a good grab game, and decent mobility.
Wario just kinda sucks. Idk. Same with Snake. Snake felt incomplete as a character.
Marth had no significant changes to him as a character and loses to pretty much every character in at least the top 11 or so slots.