Mario (SSB)/Forward smash
Mario performs a strong forwards punch where his fist increases in size. The move has average speed and range and it deals 17% with average knockback for a forward smash. It can be angled up or down (as well as slightly up or down) which will increase or decrease its damage by 1%.
The main advantages Mario's forward smash has are its range and power. While it does not shine in these areas compared to other forward smashes, it still has more range and power than most of Mario's other attacks, making it a decent option if Mario's opponent is far away from him. Additionally since the move can be angled, it also has utility as a hard hitting edgeguarding option.
The main downside to Mario's forward smash is its speed. The move does not come out until frame 16, making it his slowest attack. While this isn't particularly slow for a forward smash, it is still very slow compared to the rest of Mario's moveset, making it difficult to land or combo into. The move also has a short lasting hitbox and a decent amount of ending lag, having an FAF of 54. The move is -6 on shield, which allows most characters to grab punish Mario if they shield it, unless he spaces it or if he angles it up.
Overall, Mario's forward smash serves its purpose as a powerful KO move although it is rather unspectacular for a forward smash, having unimpressive range and being unsafe on shield. Mario is almost always better off using his up or down smash. Down smash is much faster and easier to land, while not sacrificing much KO power or range. Up smash has much less startup lag, is much more powerful, can be used out of a dash and out of shield (like all up smashes) and it can be used as an anti air, making Mario's up smash his go to option. As a result, while Mario's forward smash isn't bad, it isn't good either and is overall one of Mario's less useful moves.