League of Legends is not a great example IMO. That game has a huge grindwall. Gaining access to just the gameplay-affecting elements of the game — not even looking at the cosmetic items — would cost hundreds and hundreds of dollars and take huge amounts of play time on top of that.
Unless it has drastically changed, I was able to boot it up and play for fun right off the bat. There were no slowdowns in any matches. While some abilities were off limit to me, these were off limit to the people I was paired with as well. The only issue I've ever noticed is that heroes aren't perfectly balanced and as such it may be possible for someone to buy access to a stronger one that the rest have, but that has not ever been a noticeable problem.
That it takes 1000 hours to unlock X does not count against it when the game is quite fun without X and where X has minimal impact on the game even when someone else has X but I do not.
Think of single player RPGs where unlocking the ultimate weapons/secret characters take dozens of hours of grinding outside of the main gameplay. That does not make the RPG a grindfest. Compare this to an RPG where 2 hours have to be spent grinding for every 45 minutes of progress through the main game. That is a grindfest.
