Kosmic is the first human to beat Super Mario Bros in 4 minutes and 55 seconds, a time so good it is less than a second slower than the best tool-assisted speedrun. Mashable:
When Kosmic says he's tied with the [tool-assisted] run at 4-1, that means his inputs are matched up exactly with the program's and he can't physically do any better.
From there, Kosmic continues to nail everything almost perfectly, slipping up so minorly that most viewers who aren't familiar with the nuances of Super Mario Bros. speedruns won't even recognize when it happens.
As YouTuber and speedrunning historian points out in his thorough analysis of Super Mario Bros. speedruns, speedrunners have been whittling down the world record for well over a decade. Top runners are at a point where they can only hope to improve their times by shaving off milliseconds.
Supreme pixel-precise coordination is not enough: you have to know all the game's technical extremities to get close. Here's an explainer video (featuring one of Kosmic's earlier record runs) describing all the bugs and tricks exploited along the way.