Smite mid highlights the problems with jungle
Jungle has too much presence, from both a macro and a micro standpoint.
From a macro standpoint, their position on the map and their smite ability means they're responsible for 90% of the objectives in the game. It'd make sense right? If fights revolve around the jungler then the objectives should be close by. You take objectives when you gain leads. From a micro standpoint, Riot has been buffing junglers to the point they compete with solo laners in terms of combat capability. Through additions such as Chilling/Challenging smite, so that junglers have a damaging summoner spell, to making items that keep the junglers on par with laners.
These are the combat stats on an old AP item vs. a new one.
Spirit of the Spectral Wraith (2000g) +50 Ability power icon ability power +10% Cooldown reduction icon cooldown reduction Passive UNIQUE - SPIRIT DRAIN: Grants 2 ability power for every large monster kill (max: 15 stacks)
Runic Echo (2500g) +80 ability power +10% cooldown reduction +300 mana UNIQUE – ECHO: Gains charges upon moving or casting. At 100 charges, the next instance of ability damage you deal will expend all charges to deal 60 (+ 10% AP)
for 500 more gold, you get the 30 AP up front, 300 mana, and a weaker Luden's passive. 20 AP is 435g so this item is significantly stronger and more efficient. There should absolutely be tradeoffs for taking smite. The spell is so good for so many things. I think that mid is in an okay spot right now in terms of impacting the map (before smite), but when midlaners are taking smite, getting better powerspikes, and having a stronger impact on the map, something needs to give.
This also reflects poorly on the jungle. If these items do so much for mid lane mages, imagine what it's doing for junglers. And Riot has tried lowering the exp gains in the jungle to try bandaid fix this, but if that actually worked the best junglers in the game wouldn't be Hecarim and Karthus.
I think it's time we looked at how strong jungle is as a role and tried to lower its overall power level. The potential on the role is too high and it creates massive game disparities.