The phrase "biggest hindrance" means the main or most significant thing that is holding you back or making it difficult for you to accomplish or succeed in something. Full definition
Even if the quick heads - up notifications will cover a part of the video or game, they aren't big hindrances, and don't stay on for too long. (androidauthority.com)
These are the biggest criticisms of the movie and even they aren't too big a hindrance to enjoyment. (dvdizzy.com)
On the other hand, a thin credit file can actually put a pretty big hindrance on your finances. (mymoneycounselor.com)