How do I say this... league has harder mechanics than valorant, its very hard to know how to position yourself at all times, and the optimal way to reach your combos. The execution of the mechanics are aight if you know what you are doing the main problem is setting yourself up to do so. You need to know the ranges perfectly of the champion you are facing perfectly. Learning your own champion perfectly will get you to like bronze (if your lucky) you need to know how your champion interacts with the opposing champion. Its also a super macro heavy game involving team play, and its super hard to do that if you are paired with monkeys and theres 0 voice comms to say what you want to do. In league if your teammate is legit throwing, its nearly impossible to win. In valorant if your teams throws the worse is an ult orb and 400 creds to the enemy
Ive played league for 5 years and am Diamond. This game is hard as fuck. Also you do need insane reaction time and prediction skills or the enemy might hit game winning combos.
Also the meta changes, does the champion you main suck now? Well too bad, you are now going to lose even if you are the better player because your champ sucks. Its not like in valorant where at the end of the day you can still shoot the same gun, its very hard to pick up a new league champ. Also also you can straight up lose in the champ pick/ban screen. If their comp counters yours, or yours is bad, you have to be entirely better skilled to win. If you look at league pro games, 50% of the time they will say "x team lost because they did bad champ picks"
The skill expression between the "radiant" and "immortal" is the same as from "iron" to "immortal" challenger players are legit on a different plane of thinking. In league its super easy to plateou at a skill level. In valorant its very easy to become better mechanically, league is much harder
Think about it this way. Put a diamond player vs aspas, the diamond player will win sometes, put a diamond player vs faker and the diamond player will never win.