According to Riot's own stats, the number of detected cheaters in ranked matches doubled after they rolled out their root-level AC for League (1/400 matches -> 1/200 matches):
https://www.leagueoflegends.com/en-us/news/dev/dev-removing-cheaters-from-lol/
https://www.leagueoflegends.com/en-us/news/dev/dev-vanguard-x-lol-retrospective/
The article you cited does not support what you claim. League had a bot problem, not a cheating problem. The bots played against each other, and not against humans. This is because they were extraordinarily bad; they ran out of base and died, just to claim credit for having “played” games so the account could unlock new characters.
I spoke of Riot Games because I was comparing Leauge with their other game, Valorant.