People should learn that nobody of the three are best.
theyre all the same good, and a great team.
squirtle and ivysaur are great at building up damage,
and charizard gives the knockback sending out the foes.
Ok here are the pros and cons for the three guys copied from smashwiki.
Squirtle:
Pros:
Fast overall movement.
Fast attacks with decent damage and knockback.
Small target.
Can wall cling.
Can crawl.
Water Gun can be used to hamper horizontal recoveries and doubles as an attack.
Large disjointed hitbox on its recovery, which makes it hard to interrupt.
Can Pokémon Change with two other Pokémon.
Good aerial game.
Side Special move offers protection against most attacks.
Down aerial has good horizontal knockback on the final hit.
Pivot actually gives it a speed boost as opposed to slowing it.
Capable of shellshifting.
Up Special can score multiple hits if executed properly.
Up Smash hits a large area and kills 80-100% if uncharged.
Cons:
Pokémon Change is punishable and mandatory, due to the Stamina Mechanic and coming back as the next one in the cycle.
Very light and can be easily KO'd. (3rd lightest)
Water Gun has small range if used uncharged and as an attack, and charged does no damage.
Most attacks are fairly weak.
Low range.
Ivysaur:
Pros:
Excellent Projectiles.
Bullet seed can rack up 30-50% damage, even with good DI and can possibly turn into a combo if followed by up tilt/smash.
Vines are a huge disjointed hitbox.
Down air can spike if the opponent is hit near the bud.
Razor Leaf can go through multiple opponents and its damage will not weaken from fatigue.
B-air has long range and is great for spacing.
Up air, Down air, and Up Smash are all powerful finishers.
Dash Attack is capable of finishing an opponent at around 100% and is very quick.
Can change to two other Pokémon if necessary.
Can Crawl, although given Ivysaur's low position to the ground, its usefulness is questionable
Up Special move is a Tether Recovery and has a sweetspot at the tip of the vine with good knockback.
Up smash does serious damage and knockback, strongest in the game.
Jab combo near edge can edge guard.
All tilts have good range, damage, and spacing properties.
Cons:
Tether-only recovery is easily edge-hogged.
Change is punishable and mandatory, due to stamina and coming back as the next in the cycle.
Difficult to pick up for some due to extremely defensive style of play.
Up Special move's distorted hitbox makes it hard to accurately hit opponents.
Short jumps combined with the tether-only recovery, gives Ivysaur a very poor recovery.
KO moves are fairly slow.
Crouch does not reduce height significantly, making crawling effectively worthless.
Easy to juggle.
Charizard:
Pros:
Fast running speed.
Two midair Jumps.
Can Glide.
Has a Meteor Smash.
High-damaging, moderate-ranged attacks.
Rock Smash has huge knockback and damage.
Heavy.
Down Throw can KO at high percents.
Up Special Move gives Super Armor Frames.
Up aerial is quick, can juggle well, and works well with its multiple jumps.
Good aerial movement.
Can be switched with Ivysaur or Squirtle as the situation may require.
Long range, powerful tilt attacks.
Cons:
Very slow walk speed.
Lacks a quick, high-knockback finisher.
Glide is slow.
Large target.
Easy character to combo & juggle.
Some attacks are slow.
Pokémon Change is easily punishable and is mandatory due to the stamina mechanic and the fact that Charizard is replaced by Squirtle if KO'd.