There's that, and LeoN's not constantly telling you his character is high tier/viable compared to the copious tweets ESAM/VoiD/Dark Wizzy/Maister make about how their respective characters are the sauce lol.
On the subject of
, I would agree with the sentiment that he'll fall off eventually, but the thing is... what exactly changed between 4 and Ultimate as far as R.O.B.'s weaknesses are? He's still disproportionally fat, and the only aerials that have decent coverage below him are Shulk levels of laggy. Those were pretty much
's biggest issues, and to go further off of that, I'm going to go on a limb and say that the transition from
to
isn't nearly as big as the transition from
to
, especially when concerning R.O.B.'s gameplan/weaknesses. This leads me into my main point: What is there left to figure out in terms of exploiting R.O.B.'s weaknesses? At most, the only thing I can think of is being able to consistently parry his NAir, but for the most part, most players,
especially Smash 4 veterans, know how Ultimate R.O.B. operates in this game.
What DID change between 4 and Ultimate is giving the dude an extremely silly punish game that makes getting beaten down by R.O.B. far scarier than it has in any other Smash game. You got grabbed at +100% and didn't read the 50/50? Well, too bad, because you're probably losing your stock from that. You got caught by a now run-cancellable down tilt? You're probably eating 30~40% damage off of that, or an additional 40% if you were unfortunate enough to be caught between a Gyro when that happened. What's that, you got caught by an NAir or Gyro at 40% by the ledge? Welp, you're probably dead from Arm Rotor unless you're a giant fatty.
These things don't make his problems in disadvantage state disappear per say, but they make it so that he can afford to not the play the game
much more than he ever could in SSB4. You can treat him as your personal punching bag in the air all that you like, but if you're not going to get a kill off of it soon, there's a considerable chance he'll rip the lead you have from your hands, and we've seen this happen before (a few examples include WaDi's and Samsora's set in CEO and the multiple moments in Super Smash Con where Rafi-X took a stock off Nairo or ESAM at absurdly low percents). Long story short, R.O.B. has a much bigger baloney comeback factor in the game, which really emphasizes how insignificant percentage leads can feel in this game.
One last point I want to make is that it's kinda hard to imagine R.O.B. becoming irrelevant in a world where there's probably 50+ R.O.B.s running around: We have the big boys zackray and WaDi, but outside of that, there's 8BitMan, Raffi-X, OCEAN, Dill, Grayson, Mj, Somo, Benny&TheJets, KiraFlax, GwJ, etc. and probably a ton more I missed. Compare this to a character like
, another character who was considered amazing early on. Yet now that Salem's dropped him, T's pretty much the only major player left to represent him. What I'm getting at is that characters like Link and Ike are far more susceptible to falling given their small playerbase compared to R.O.B., who's pretty much got an entire armada backing him up. And unless everyone suddenly decides to collectively band together to drop him Cloud style, I can't really see R.O.B. going anywhere but up.