Kirby has 6 jumps and his Fireball will trade damage with practically anything. Yes, he lacks in KO power but he makes up for this with the cheapass instakill that is the Swallowcide Cancel. Using aerials between jumps gives him all the recovery he'll ever need to boot so his only real flaws are damage output and low weight, both of which are noticably worse in the american versions.
Whether you like it or not, Kirby is only the second worst character in PAL Melee and his tricks make him one of the best characters for a beginner. Pichu, while full of potential, is worse in a competetive sense, is harder to pick up and is far more similar to other cast members.
I love Pichu but don't you dare try and tell me he's better than Kirby.
The only thing Kirby has over Pichu is weight (Kirby's is still garbage even in PAL Melee). He has virtually no KO power outside of U-Air, which is difficult to land. Swallowcide is hard to set up on anyone with even the littlest bit of skill and is easily punished if missed. Even though F-Throw and B-Throw can Kirbycide, they can be escaped, unlike any other throws in the game. His aerials lack priority and his low air speed makes him easy to edge guard, and Final Cutter is one of the worst recovery moves in the game. They didn't really fix his awful damage output in PAL either. How beginner-friendly he is doesn't matter either way, Fox is very hard to learn, but that doesn't mean he isn't Top Tier. Kirby, no matter what way you look at it, is the worst character in Melee competitively.
You also forget to mention the upsides to Pichu. Despite having among the worst survivability in the game, tied with Mr. Game & Watch and Kirby, he atleast has decent damaging abilities and amazing KO power on several of his moves (ex. F-Smash and U-Smash). Unlike Kirby, he is also fast, fitting into the style of Melee. Pichu also has gimping abilities with his N-Air, which is something Kirby can't do. WIth a combination of his good air speed, Skull Bash, and Agility, Pichu has decent recovry that is also rather safe to use.
Even though Pichu is one of the worst characters in the game (22nd or 23rd IMO), there is no denying that Kirby is better than Pichu in any way outside of weight (either way, Pichu and Kirby still die around the same percent).