When you look at bigger backs like Toby Gerhart and Brian Leonard, who ran really fast 40s for their size, a big White back has to literally run a 4.40 and likely even faster to get a look, and even then a litany of excuses will be offered as to why they're "not capable" of being a running back, in sharp contrast to the hundred or so Black ones in the league at any given time. Travis Jervey was 6'0" and 230 pounds with blazing speed -- NFL's Fastest Man speed -- and was always treated as nothing more than a special teams player the entire time he was in the NFL. Christian McCaffrey was an outlier for reasons we've mentioned many times and of course he was certainly fast enough.
But I don't want to be overly negative. There's clearly been an uptick in White RBs getting some play at both FBS and FCS schools, especially the big programs as there's always been a sprinkling of really good White backs at the smaller schools, though of course one after another they didn't get a legit opportunity in the NFL. It's nice to see, and as I've written before I believe Caste Football has made a dent in the prevailing narrative which stood unchallenged for decades. A long long way to go, but any kind of incremental progress in any area of this "woke" anti-White society is always extremely rare and shouldn't be minimized.