The fish bite faster with bait than without it. This is not up for debate. The improvement from no bait is that it halves the time between bites, it's literally the whole point of this game mechanic. And selling bait is pointless, it is only worth 1g per piece
As for samples on bite times, I have literally thousands of hours in this game, having started hundreds of farms, and a large percentage of them have featured lots of early fishing to fund whatever theme I'm pursuing. In particular, on days 2 and 3 I will literally fish from as soon as I can get to the water until passing out at 2am, about 19 hours of fishing. Once you factor in the bubbles, I would estimate that the long term rate with bait is up near 5 bites per hour. Of course not all of them will be actual fish, there's algae and trash as well, but that's just RNG. Without bait, before I get the Fiberglass Rod, I'd estimate you're looking at maybe 2.5 bites per hour.
If I'm fishing at the mountain lake in spring, I'd further estimate that my earning rate with bait is around 450g per hour. So, without the bait, the bite time would double, meaning it would cost me over 200g per hour not to use bait.
TL;DR - use bait