Can we please get better detection for boosted accounts in Diamond?

If I can look at a someone's match history and see that it's a brand new account that climbed to Master with 65% win rate, and went 3-21 down to Diamond III MMR with completely different champions from the ones it used to climb, it's very clear that this is a player who bought a boosted account. This scenario is becoming extremely common in Diamond, and it has a major impact on everyone else, if these boosted player are forcing that many losses before they get banned. I really don't understand why the system can't detect extreme spikes in win rate like this, along with other factors, like sudden changes in champion pool and location.
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