Jungling doesn't require skill or decision making anymore :(
With the changes to the Jungle first halfway through season 6 and now in preseason 7, I don't feel like being a good jungler matters anymore. Let me explain. LONG TEXT AHEAD, TL;DR FOR LAZY PEOPLE AT THE BOTTOM
First, when Global Buff Timers were introduced, a big part of being a good jungler was removed from the game. Before that I used to be able to keep track of when enemy buffs would spawn, where their jungler would likely be at any given moment (if they played "correctly"), what camps would be up, and what scuttle crab would likely be taken just by knowing the enemy jungle route. And that made me a good jungler. Now I don't even bother to keep up with that past the first clear and a half because the map will tell me which buff will spawn and exactly when it will spawn. I can use that to pretty much do all the work I had to do mentally for me and still be just as effective. So if I didn't know how to do all that, I would be just as effective a jungler now as I was then. So in that way, something that separated good junglers from not as good ones is now gone.
This preseason, they removed smite buffs and added plants. Smite buffs provided interesting choices for a jungler to make. If you bought a combat smite, you had to make a choice of whether or not you wanted a smite buff or you wanted to save your smite for combat. If you were going to invade or gank you should grab raptor smite if possible, if you're going to power farm you should grab krug or gromp buffs to do it healthier or faster, if you need the stuns on your autos to clear well you should start red side, but if you're tanky with slow autos you should start blue side (Also some junglers it was a good choice to skip your buffs entirely either to get to level 6 faster or because you didn't need either of them and they just slowed you down and did a lot of damage, but now I don't get to make that choice either). All of these were interesting choices that I no longer get to make as a jungler. But instead we have plants. Don't get me wrong, I'm not hating on plants, but they're a poor replacement for smite buffs because they provide zero meaningful choices to make as a jungler. You just use plants on cooldown so that the enemy doesn't get them. They, when combined with the health on every smite, also kinda take the risk out of jungling.
Previously, if you were playing a low health clear jungler against someone with some invade pressure, you had to make a choice to either back after clearing your first half of the jungle and risk losing your other half of your jungle, risk getting caught doing scuttle to restore some hp, or use your wards to protect you instead of using them to ward the enemy jungle or ward for your laners and hope your laners could respond if you got invaded. Now you just don't do your raptors, smite on cd, and take the health plant to regen your health and mana so that you can stay full hp in the jungle. On top of that, the plants take the risk out of invading. Used to if I wanted to invade, I had to take the risk that a) the buff was indeed up like I thought it was, b) that the enemy jungler didn't catch me on it, and c) that I didn't walk over wards and get collapsed on by enemy laners. If I wanted to invade, I would go get Raptor smite, ward where their nearest laner would come from, and bring a pink with me in case I already used my raptor smite by the time I got to the buff I wanted to take. That's a lot of preperation and risk for an invade, but that's what made it feel so great when it worked. Now you just scrying plant their jungler and see whether or not their jungler is there, what camps are up, and where their wards are. Even if something does go wrong, I can just satchel plant away. Very low risk.
And as far as the argument of, "well raptor smite was always the best smite so there wasn't any meaningful choice", first off I disagree. It was very good, but that didn't take away your choices, only the removal of smite buffs did. And besides, if there's anything I've learned, it's that anything in League can be good enough if the numbers are there. If Gromp buff scaled better, it would be a more meaningful alternative, if the Krug buff gave you more bonus damage to objectives, it would be a more meaningful alternative. Anything can work if the numbers are there. But Riot kinda just took the easy way out and rather than try to tune them so that they provided more meaningful choice they kinda just said "we haven't balanced them after a year, so we're removing them entirely."
All in all, to be honest, I don't jungle any more. There's no point in trying to be good at jungling because a mediocre jungler can be just as effective as a good jungler as long as they know how to gank because just about everything else in the jungle is done for you.
TL;DR The addition of Global Buff Timers made junglers that could track enemy buffs without them less set apart from junglers that couldn't. The removal of Smite buffs in favor of plants further simplifies jungling by removing the meaningful choices that came with them, even though they weren't balanced (Raptor Smite was the best) Riot never really tweaked them to try and balance them. Scrying plant and the health/mana plant make doing a low health clear jungler way too easy when combined with the fact that every smite heals you now, Scrying plant took the work out of invading (you can see whether they're there, what camps are up, and where their wards are), and the wall jump plant took the risk out of it since almost all junglers have a dash now you'll have an extra escape. There is much less of a difference between a good jungler and a bad jungler than there used to be because of the addition of Global Buff Timers, the removal of Smite Buffs, and the addition of Plants.