TL;DR: Jg is too impactful for how difficult it is to learn and how often it gets filled.
I agree, but I think jg in general has become too overvalued by how the game has changed. Very few people will disagree that most games are won/lost in the jungle.
Every since the crabs were added and early fights were forced, there's more pressure than ever to play high risk, high reward junglers (damage picks) and succeed early. Even a single death can feel like you're set 10 mins behind your opposing jungler. Jg variety in general is incredibly worse than it has ever been with only a handful of picks even really being considered viable in higher elo.
In addition to this, herald was added and given huge lane impact, further increasing the value of a good obj focused jg. Now with the 2nd dragon rework, junglers are pressured more than ever to have flawless rotations on the map to prioritize objs, in addition to being forced to deal with hard stomp picks that very few laners can beat (morde, akali - you might disagree, but very few match ups have an effective to way to deal with these 2).
The shear fact is the position snowballs way too hard. If you manage to pick the other jg a single time you have full map control and can basically free farm their jungle. This forces the opposing lanes to play a totally different game as they have basically no jg support for ganks/counterganks and it instantly becomes their responsibility to watch out for invades so their jg isn't forced further behind, losing all possible dragon pressure.
The impact of the jg role is just off the wall compared to basically every other position IMO. It's not hard to understand why it's one of the most filled positions in consideration of the risk of failure. Learning to jg is nearly impossible for entry level players and the impact you have, whether you're winning or not, is higher than ever. I remember when having good clear paths and knowing your champ's gank patterns was enough, but now the drag buffs are just so impactful that you can't afford to not be optimal every game. It took me seasons to jg efficiently and with the recent changes, I still feel useless some games.