Dota 2 does just fine giving you literally everything from the start.
Im at a huge strategic disadvantage if I don't have all the champions, masteries, runes and summoner spells yet Riot puts me against people that do on a regular basis. If all these spells and whatnot did nothing it would be fine since I wouldn't be in a worse off position for not having them. The only difference that should exist between a level 1 player and a level 30 player is game experience, not how many runes/masteries/champions they have.
If I was given all 12 spells, runes, masteries and characters I would just try whatever seemed interesting to me out every new game and go from there. I wouldn't "freeze" and I doubt most other people would either.
This idea that we have to string people along for over 100 hours of babysitting and handholding and not letting them experience the entirety of the content is really odd to me. Instead for some reason we just let them not have access to even a small percentage of the content forcing them to make critical mistakes in how to play the game.
I've played this game for over 3 years now, but when I started I waited until one of the characters I actually wanted to play was free and stopped when he wasnt until a friend of mine bought it for me. Why is a game that is all about playing your "Legend" or fantasy against others limit which one Im allowed to have? The only real reason is financially, there is nothing game design related behind it. All answers Ive seen from Riot are poorly constructed arguments about how they are afraid it would scare off new players. Yeah being able to look at a large grid of colorful and interesting characters and pick which ones I want to play is so scary right?
Sure introducing someone to Yugioh by showing them literally every single card might be hard at first, but honestly they would grasp the idea of the game and what works and what doesn't in a much faster and more enjoyable manner than one who just goes pack by pack.
MOBAs are all about knowing everything about the characters, spells etc., and you do all this just by playing the game. Forcing the player to constantly think about what to try next, what to change and giving them a slew of new opponents constantly will honestly breed better players than introducing them to core concepts 1 at a time.
I can't tell you how many of the new League players I have helped struggled heavily at the start because they either couldn't play the character they wanted because they had to buy it, couldn't optimally lane because of lack of runes or masteries, couldn't do a certain strategy they wanted to try out because they didnt have the summoner spell etc.,
All of your examples, Zelda/WoW etc., are progression based games. Skill is entirely based on level and where you have progressed in the game and story. League and Dota or any other MOBAs are not progression based. League just forces a progression system onto players instead of using an actual MMR or rating system. The only progression in the game of League is farming and getting items and levels. Thats it. Its a game about playing several different characters in several different strategies. In a game that is all about picking a "Hero" you want to play and defeating others, why would we limit what strategic options people are allowed to use just because we are afraid its "too overwhelming"
Its that annoying concept that a lot of Nintendo games do where you cant do a certain move, sometimes even jumping, until you get to a certain point and its unlocked for you. Like you have to prove you are a rational human being in order to be taken seriously and allowed to actually play the game. I dont fucking understand this approach.