The core ideas remained the same, only difference is that they've got more roadblocks now which makes it considerably tricker (security measures in the OS + anti-cheat + encryption/DRM + server-side checks etc).

But modern day cheating goes beyond memory editing, for instance there are things like aimbots which can work at the GPU/driver level, or input automation/macros which work completely ouside of the game so normal anticheat measures may not prevent it.