Not always. Hikaru does speedruns[1] using an alt acct with entry-level ELO to race to ELO 3000. I've watched a fair bit of this, and seen him encounter the odd cheater or suspect game, but much nearer 1% than 10% of the time.
1: e.g.: https://www.youtube.com/watch?v=iOd222WIEk8
Not always. Hikaru does speedruns[1] using an alt acct with entry-level ELO to race to ELO 3000. I've watched a fair bit of this, and seen him encounter the odd cheater or suspect game, but much nearer 1% than 10% of the time.
1: e.g.: https://www.youtube.com/watch?v=iOd222WIEk8