This game is becoming harder for new players to learn

For new people just starting an account playing to lvl 30 it is just overwhelming to learn all the champions and their capabilities. Also, there's a lot of items to learn. People don't know why they need items, what armor does, how certain champs scale, what ap or ad does, what is a cs...etc... There is so much to learn about this game for a newbie.

Then to actually get good at the game you need to learn all the theory, like:

When is a good time to baron? What should I do when enemy team shows up while we're doing baron? When should I back? Should I hit that cs? What should I buy against this team? When should I trade? Where and when should I place a ward? Is it better to kill a wind drake or hit enemy inhibitors? And so much more....

I started playing at beginning of season 5. I was freaking bad and mained warwick. I didn't even know I was bad! Only recently have I realized how bad I really am, and how much I need to improve, and I'm ranked in the top 14% of players at this point. My goal this year is to reach diamond 5 but idk if i can do it because I suspect there is just going to be more and more things I uncover along the way that I really suck at and will need to make time investments into fixing those mistakes. But best to shoot for diamond and barely miss than goal for bronze 5 and hit it dead on tho... :)

I imagine it was much easier to learn the game when it was in beta or season 1 with around 20 champs and less items or whatever it began with. At this point people hit lvl 30 and play ranked and just totally suck d because the game is so complex they have no freaking idea what they are doing because they haven't really learned even the basics by the time they get to ranked... because of this I kind of wonder just how much new players just give up at the game and do something else. I wonder what Riot's retention rate of new players is today compared to when they began.