Naruto's not like other characters he accesses RSM via fusion of Kurama cloak. That's because he wasn't born with it or wasn't the actual 10 tails jin, rather he was a pseudo jin. The SPSM(TSB) version was going to get nerfed that was the Pseudo 10 tails mode. With the loss of the TSBs Naruto lost the remainder of the beast chakra, I think.
Edit, there was the exception of when he used it against Madara to save Guy. But that was likely fuelled by Yang seal of Hogaromo. Sasuke also used a jutsu that could hurt Limbo with the seal/chakra.
Btw if Sasuke was severely nerfed during the fight and now is even more nerfed I don't see Naruto getting a free pass.
I honestly prefer teen Naruto and how his modes/power we're handled back then over this ambiguous mess known as hokage Naruto.
While I agree with you RSM just amps up abilities to peak levels(Rokudo chakra etc), and gives extrasensory powers on another level. It's even argued that Naruto has lost RSM as he would've used it to find Sakura instead of TSM, during Gaiden.
It's all for Boruto's story Dattebasa, everybody has to be nerfed or fodderised. How else is he going to shine, it's even possible next chapter Naruto gets solo'd and Boruto steps in to solo Delta, or force a retreat.
I get what you're saying and all. Now, I have certain reasons why I believe that Naruto in theory should still have the power we saw in the war, but that is not what I want to discuss right now.
What really just pisses me off is the fact that we never really got any formal verbal acknowledgement of Naruto losing RSM, and it was never initially established as a temporary power up either. I feel that if an author gives a main character a major powerup, they should let us know explicitly when it is going to be temporary or if it can run out.
For example, when Kakashi got DMS, we were specifically told from the beginning that it was limited time only, so it came as no surprise when the power left him.
However, we never got any such statements regarding Naruto's RSM. They just randomly decided to not have Naruto use it again!
To add insult to injury, we don't even get a verbal reference to it! Not in the Last. Not in Gaiden. Not in Boruto.
If Naruto truly lost all that power then all it would take for Kishi to tell us this is a simple dialogue as such:
Sasuke: "Naruto, whatever happened to that power you got from the sage of the six paths?"
Naruto: "My bijuu chakara ran out, so I can't use that anymore".
Or if Naruto by chance does still have it, we could get a dialogue like this:
Momoshiki (while extracting Kurama's chakara): I see you also have more of those beast chakaras inside of you aside from just that fox. (Evil laugh) That will make for much better pills.
Do you see what I mean? Simple dialogue could have prevented this confusion and debate that has gone on in the fandom for years! Did Kishi have the decency to even give us that though? No!
Heck, if he wanted it to be temporary, he even could have just had Hagoromo state this from the beginning!
Example:
Hagoromo (when telling Naruto and Sasuke to raise their dominant hands): I am going to give you a gift, but use it wisely. There is a limited amount and it will eventually run out.
or
Hagoromo: "Naruto, you will be the meeting place for the bijuus since you have the chakara of all 9 bijuus. Even once that chakara runs out, you will still maintain a telepathic link with the bijuus".
Anything like that would have been fine!
But noooooo! We can't even get a verbal mention!
Then Kishi has to screw with us even more with hokage Naruto's freaking design for whatever the heck that mode is!
If it is BSM, then why not just have Naruto keep the pigmentation? He had pigmentation in The Last and he has it in normal toad sage mode, so then what is the deal with this BSM/RSM? Like seriously! Why did he have to screw around with it like this?
On another note:
Did Kishi just hate Naruto or something? Like seriously! He gives Sasuke an epic permanent powerup (rinnegan) and gives Naruto only a temporary powerup?
wtf? I know you are going to say that rinnegan is a KKG while RSM is not, and I understand all that, but Kishi was the author. He could have found some way to give Naruto a permanent powerup whether it was RSM or something else (and no I don't mean that redundant full Kurama crap).
It's like Kishi just was bent on keeping Naruto weak and not versatile!
One more thing:
You say that Sasuke is nerfed now, and that is true to an extent since he is missing an arm. However, that has never actually seemed to affect Sasuke's jutsus usage. Sasuke hasn't lost a single ability. He can even still use chibaku tensei. Heck, Sasuke has even gained new abilities that he didn't have before such as the dimensional portals (or shadow clone jutsu which should allow him to make a susanoo army like Edo Madara).
Meanwhile, Naruto seemingly has actually lost several useful abilities such as:
Truth Seeking Balls (which can be used for several purposes)
Flight
Bijuu KKG such as magnet release (which grants him things like sealing jutsus)
Etc...
And what does Naruto have to make up for that?
Nothing!