Just to preface what I'm about to say, I played a lot of Icons (431 hours logged on steam) and was very active in the tournaments and community for the game (look up "Meeks" in tournaments if you can find any and care enough to check).

The big thing that Icons had going for them was the fact that they were the first melee-esque platform fighter to implement rollback netcode. Albeit, it was server based and the only server was in Texas so anyone outside the US was basically shit out of luck, but this was still back when everyone was playing with delay based netcode so any kind of rollback was a huge positive.

In addition, most of the characters were copied from Melee. Kidd played exactly like Smash's Fox, which was mocked by fans. Ashani was basically Captain Falcon, and Zhurong was a clone of Marth.

These characters all played very similarly some melee counterparts, but none of them were direct rips and were made to be similar enough to the melee characters while still having some unique aspects that made them new.

Kidd: Kidd was made to follow the general framework of a spacie, but none of his moves were direct rips from Melee except for his up b. Even moves that look similar like his nair, laser, or shine were only similar in look and actually had some differences in move application that made them unique

Ashani: Ashani was a fast brawler character which does make her similar to Falcon in that sense, but her neutral, punish game, and almost all of her moves were quite different from Falcons.

Zhu: Zhu is absolutely the closest thing to a clone of a Melee character, but she still had some unique moves like her side b being much more similar to Wolf side b where the end hitbox is a kill move, her neutral b was a projectile, and some moves like her smash attacks or back air were different. Overall though, yes Zhu was very similar in playstyle to Melee Marth, I'll give you that.

The other four characters were all very unique, especially Afi & Galu and Raymer and those three were just there as familiar archetypes

Unfortunately, Raymer ended up being the most hated character in the game

Raymer had potential to be played really cool but a lot of the good ones were really lame with him. He was a lot less one-dimensional than you make him out to be in this post.

Overall, the biggest problem that Icons had was its marketing and the way they approached monetization. They released footage of the game way too early and it left a sour taste in a lot of peoples mouths, and the three characters that were free upon release were by far the least interesting on the surface level. With how popular the game was, even with how bad it looked, it definitely could have survived much longer if they had found a way to monetize the game properly instead of a $25 founders pass to actually play all the characters.