I'm not saying it's bad that people have to practice to get good at a game.
I've answered this so many times because Melee has so many unique characteristics/cancels, but it ultimately comes down to adding options to the players and allowing for unique play styles.
In Melee there are numerous things that people consider "for no reason," which is a fair assumption on paper, but in real play changes things substantially from player to player. I think a casual Smash observer may not realize it because they haven't experienced it and because they may only watch Smash during the top 8 of a tournament where there are players SOOO GOOOOD we call them gods, but outside of those players, but honestly still applying to them, these "complex controls for no reason," actually have interesting side effects.
So here are a few skills that are important, but can be done to different degrees of excellence.
Wavedashing (also platform dashing)
DI
Smash DI
Moon walking
Here are a few skills that can be done either successfully or unsuccessfully, binary outcomes.
L Canceling
Edge Canceling
Pivoting
Shield Dropping
For simplicity I'll refer to the top skills as Degree Skills and the bottom skills as Binary Skills.
Degree skills are interesting because they can be done better or worse between players, but even being able to consciously pay attention to these skills can improve your game even if you aren't perfect at them.
Binary Skills are skills that 100% make you a better player if you simply press or time the correct inputs.
However in Melee there are still times in which you may not want to risk an L Cancel if you're confident that you can land an edge cancel. If you did an edge cancel and pushed L you'd actually end up in a worse situation than if you hadn't pushed L.
To compare Melee to a sport.
Degree Skills are like your ability to dribble, sprint, hold a ball tightly, etc.
Binary Skills are things like catch a ball, throw a three pointer, etc
A good competitive game has a balance of degree skills and binary skills as well as a good combination between requiring mental determination and physical resolve.
For someone that wants to just play a game for fun after work, Melee probably doesn't sound to enticing, but if you love the beauty of Melee play, you would obviously want to invest.