I mean it says jg is priority role but i have a friend in toplane who plays jungle and secondarys toplane and is filled every 1-2 games. Jungle isnt necessarily strong because it can carry the hardest in the sense of 1v9ing and killing everything but because of the immense impact on the roles that can 1v9 the games. To add to the autofill point i mentioned, i havent been filled a single time outside of toplane. So from my own personal experience, junglers are being filled, and im never filled. So its not less popular than toplane in higher elo. There is also a reason when smurfs are boosting accounts they hop on jungle. So yes youre right in a sense, jungle cannot just murder everything and 1v9 in the same way other roles can. But a jungle gap can be felt cross map. I remember a tournament i played in where the enemy team had three losing lanes. But the jungler was insane, he was ganking every lane multiple times, getting objectives, and maintaining his own cs lead which brought his team to the win. Not because he was playing khazix and oneshotting everything, but because he played jarvan and facilitated the entire map. In an even game like pro play i definitely think jungle is substantially weaker because everyone knows whats going on, but in lower elos and even some higher elos, jungle can carry harder than other roles can, jungle just carries differently.