It is inevitable, but plateaus happen during training.
But if you look at the phenoms that dominate competition and blast through the ranks in a matter of 3, 4, or 5 years, something very different is happening. Are they better learners? Do they have better instruction? Surely something in their training differs.
In my opinion, I believe it really comes down to examining the weakest part of your game.
Watching matches of yours taped on video help the most in this regard (especially matches you lost).
An expert/instructor may watch the match and conclude that you did everything wrong and should change even basic strategy (which you may not have even known until asking)
Someone less experienced may point out just one flaw.
Regardless it is important to get everyone's opinion/advice and adjust accordingly.
Asking "where did I get stuck in this match" and "where did I have no answer to what my opponent did" often times leads to a very quick answer in terms of what to work on next (and breaks plateaus).
Now a video on guard passing by Vitor Shaolin Ribiero