Sheik is one of the toughest top tier characters to master with an ultimate reliance on excruciatingly accurate hitboxes, it's important to recognize that top level Sheik play comes with an insane amount of experience to be able to execute perfectly, which against better players obviously is incredibly apparent. Sheik is forced to react better and create optimal scenarios for her. It's harder to create those scenarios in the neutral, especially in certain MU's, primarily due to things like speed, dash dance and honestly just amount of options to create mix-ups and opportuinities as you work towards pushing you opponent out of center stage, even with a lot of hitboxes that lose trades in top MU's.
Players with experience fighting Sheik know how easy a combo can string together off of landing one hit in the neutral. She is a great combo weight, so if you are losing to spammy tilts or something, don't blame the effort.
Ie. Tech chasing, optimal edge guards.
Sheik tech may not be a vast tree of flashy things, but proficient and optimal movement is an absolute must to passing through certain plateaus. Anyone sleeping on sheik talent is annoying and is holding themselves back if they don't fully believe that Sheiks are working hard, if not harder than a lot of other characters, just because tilts are more spammable than the other cast.
I have played roughly 2k hours of Sheik over the last year and been to many tournaments. At first, new players may seem susceptible to getting ****in rocked, is because new players don't respect the players, but ultimately they don't respect the game enough yet.
They don't know a lot about this game, they make poor choices, and they make choices regardless of what your opponent does. When you play the game with this mindset, suddenly it's a little more understandable why scrub A keeps walking into my poorly spaced dash attack or something and I get free kills. I wouldn't be quick to call Sheik braindead, but instead her low level opponents who refuse to respect the character.
But that only lasts for so long. Suddenly Dash Attack, a super free kill against noobs, becomes the most scary move to throw out against an experienced player. Because honestly unless your desperate and fishing for a kill, or covering your opponent coming down, it's pretty much a free kill if optimally punished.
Okay, enough with this haha. I just don't understand why people would destroy the beauty of Sheik's style by calling her Braindead, when her actions generate and create a completely beautiful neutral exchange with every top tier!