Yes. The national polls were generally close (within a point or two, and again, I'm not saying there were NO national polls that had Sanders ahead), but the swing state polls (which are really the only things that matter) showed Biden in a significantly better position than Sanders.
General favourability numbers were also close, but Bernie's unfavourables were significantly higher than Biden's too (understandably so, I guess)
Fair enough, I didn't drill down to regional polls. No national polls, in fairness it looks pretty close. Bidens peak lead appears to be 10, Sanders 9. At certain moment each of them had a slightly bigger lead over Trump, and I probably looked at a time when Sanders was ahead,
Either way, not allowing Sanders to run, was an ideological not a practical decision, which is sort of the core point here.