Same with dungeon design, which is as much of a feature in crawler as it can be in an FPS.
There have even been FPS games specifically going for RPG/crawler feel - see Strife or Hexen series.
Add System Shock to that list. It had awesome "dungeon".
Gladly, especially given that it is a
game with absolutely no RPG elements.
Anyway, dungeons don't have to be dungeons, and while Skyrim's actual dungeons are mostly linear mess (though not all of them, more spacious ones can have quite a bit of room for tactics), you also have hostile overland locations that are mostly interesting due to their openness and freedom of approach. LoL overland locations, OTOH are mostly mazes pretending to be forests.
Your approach not differs from my, but you are using too few facets.
So what would be those extra facets that make LoL a good RPG?
Not a good game, or even good experience - for example Oblivion is an absolutely abysmal game and experience despite being far better RPG than LoL - but a good RPG.
I can guarantee you that whatever such factor you choose, you will either end up arbitrarily rejecting a number of unquestionable RPGs, or including a number of definitely not RPGs.
Your whole party in LoL had less stats and was doing much less with them than single Skyrim character.
Academagia had slightly less stats and much more skills than Skyrim, but it still not RPG.
I consider stats to include all free parameters that can be altered as a result of chargen and character development - this means both attributes and skills.
For example Morrowind had 35 stats - 27 skills and 8 attributes. It also had maximum health, magicka and fatigue, but those weren't stats in RPG sense, because they weren't free parameters and couldn't be changed independently of attributes during generation or development. A stat in RPG sense must also require tradeoff between raising it and some other stat*.
Skyrim has 21 stats - 18 skills and three attributes also doubling as resource pools (health, magicka, stamina). Resource pools are included this time, because they can increase independently of any other stat. There is also perk system adding quite a bit of extra complexity but we don't need to consider that now.
LoL has 3 stats - including 3 skills. It's resource pools (health and mana) are not stats in RPG sense because they don't change independently during character development.
Mutiplied by 3 (max people in party) it gives us 9 stats total.
RPG-ness should be judged as a complex variable. For example, you forgot about "other genre elements" (think of arcade sequences in Obitus) and elusive "decline!1!1" parameters.
It's definitely a complex variable.
However:
I don't care about the other genre elements. Sure, if they change the narrative focus of the game, they may be decisive, for example an RTS will be an RTS even if your units have character system surpassing in depth any of the RPGs in existence, simply because it's gameplay doesn't focus on the fate of few individuals (protagonist/adventuring party), but on large scale military operations where individuals are mere pawns. But if the other genre has roughly the same focus (for example RPG and FPS both focus on fates, actions and goals of a single or small bunch of characters**), it can at best qualify the game for hybrid status.
Decline parameters are inherently relative. They can be seen in the context of the series - Skyrim mostly declines the series mechanically (a little bit, because overall its mechanics works better than oblivious mechanics did and it does introduce both perks, and ways for characters to avoid converging towards the endgame), but inclines it as a whole compared to last instalment (still way below Morrowind and Daggerfall, but a rising trend nevertheless). They can also be seen in the context of the state of the genre or gaming market as a whole, in which case Skyrim is better than par and therefore incline, while Lands of Lore was indisputable decline back then and would still be decline now - few stats, no item descriptions or stats, simplistic mechanics, lack of character death (unless scripted), linearity and so on.
Finally, Skyrim possesses one of the crucial characteristics of an RPG - making different builds play differently - ranged character will work differently than melee one, summons or stealth will also make difference in making different approaches viable or not. This is obviously amplified and improved by mods, but also present in base game.
LoL, OTOH doesn't posses this characteristic.
In conclusion, LoL is better RPG than Skyrim. Just because more stats, NPC interaction, etc. don't balance shittyness of other aspects.
Conclusions don't work like this.
You need to show how you arrived at them.
We'll call it BSBCodex. Or BSBGamer. Something like that.
International Inclined Gaming Network (IIGN).
Bonus points for luring in some typo prone ignoramuses and smacking them in the face with the Truth(TM).
BSBCodex will be what's left here.
*) Not accounting for RPG sense would also make many pure action games RPGs, for instance base HP count and ammo capacity increase in Quake 2 thanks to adrenaline and ammo packs/bandoliers, but those aren't stats in RPG sense, because they aren't intrinsically tied in some sort of tradeoff, character stats in quite a few jPGs are also not stats in RPG sense, because they are functions of level alone.
**) By narrative focus I mean the way gameplay events can be described in-universe (so no metagame nor abstraction layer, only the actual events, without reference to classes, hitpoints, levels, or damage multipliers on headshots).
Pretty much every RPG could be ported into a non-RPG action game and vice versa without changing this description.
OTOH you wouldn't be able to port games between RPG and RTS or RTS and FPS genres this way because they frankly have too different scopes.
Gameplay based narrative of Baldur's Gate RTS or Starcraft FPS would be very, very different to narratives created by their original versions.