The South Park episode about freemium game is very good at explaining how the freemium market model is based on addiction.
Right, xp/ip boosts are just hats. New characters you buy are just hats. No in game effect, LoL.
IP boost allows you to buy runes quickly, this happens outside the game. Runes have in-game effects, but the difference between T2 (which are extremely easy to buy without spending a dime) and T3 are minor.
I played LoL for years without spending a single penny in it, and I never were under the impression that the game was purposely made boring to force me to buy in-game items.
Freemiums game feels that way. At first, everyting is fun, and they even give you some 'free' currency to hook you on spending, and after a few hour, if you don't pay, the game becomes boring as fuck, because everything take hours.
It is there for convenience sake but Riot certainly goes out of its way to make creating a viable alternate account rather inconvenient. Being F2P I guess they have to have diverse revenue sources.
All this talk about "cheat" or "increasing competitiveness" is just nonsense.
Then again, you haven't discussed in good faith from the get go (which is funny, since I primarily game on pc), so I expect you don't actually want to grok these differences.
You say flatly that 'LOL boosts do not increase competitiveness' but this is frankly completely false. An identical clone of myself playing on an account after $300 worth of xp and IP boosts will simply be much stronger than I am with f2p account. Eventually I may catch up but 'eventually' happens in clash of clans too.