When I used to play LoL, like 5-7 years ago, I was playing a rate of like 3-4 hours daily, which barely scraped by the amount of essence needed to buy the next releases champion, let alone the runes system they had introduced at the time (don’t know if it’s still around) which had a fairly dramatic impact on the early game especially for specific characters.

That is, while technically the game could be played purely on free tier and eliminate any competitive advantage… it requires a lot of effort to keep up. Not nearly as bad things like FarmVille used to pull, but definitely enough to say that ponying up cash is eventually needed.

And having more options available to you (both characters and runesets or whatever they do now) is definitely an advantage, and a significant one at that