Nasus needs a tweak there no player in League that can honestly say his overly passive play-stlye is in anyway at all interactive with the lane or rewarding for good play, much less has any REAL counter play. It's not a problem that Nasus is a late game monster who only has to farm to be quite literately "huge". But dominating Late game presence does not equate to getting 6, and quite frankly thats where he is most noticeable. It's not just the ultimate, because if that were so Renekton would feel just as oppressive if not more, and he is not in the slightest.
Nasus is supposed to be weak early game, but in practice he's really not that weak at all relatively speaking. A lot of people mistake the meekness for weakness, meekness representing a preferred passive play-style. You don't need to have hard cc and extreme kill potential (be pantheon or jax essentially) in the first two or three levels to have decent or relevant early game. Sustain is a thing and while people like to say his early game sustain is not a thing, it becomes real relevant real fast, with no real counterplay in a 1v1 scenario and much more risk than to be initially thought. I admit it would make much more sense to blame the community than riot on this point, because people quite frankly REFUSE to help the top laner shut down Nasus when he is at his most useless/vulnerable (5-10 minutes into the game), and think it's a simple meager task to do solo when it's not.
But his early game doesnt feel like the early game it should be honestly, there are adc hyper carries with longer stretches of weakness or greater varieties of "power spiking" which seem more balanced than him, then again that's a different lane entirely. Nonetheless Nasus isn't some "oh lol troll pick gonna wreck". No he has seen LCS play, he isnt outdated, he can be very successful in current popular meta comps and in the right hands is deceptively a real issue. What makes him good/viable is his simplicity and great scaling/tools to split push/ decent 1v1 ability . Weakening his early game sustain, and buffing his mid-late game sustain seems appropriate in my opinion.