I'm not sure which "people" to whom you are referring, but it seems like approximately half of the comments on HM threads are assuming that everyone in the B1G West will be worse, and we'll definitely be better. If people really were saying what you're saying, I wouldn't have started this thread.
I put the over/under for Nebraska in 2019 at 8-4, but I see a very wide range of plausible outcomes. If Nebraska goes 9-3, it would be great. If they go 11-1, Frost should sweep every Coach-of-the-Year honor again. On the other hand, we're one or two injuries away from struggling to be bowl eligible. In the offseason fans seem to always assume that none of our players will get hurt, everyone will improve on our side, but nobody will improve on the other side. The only team in the B1G West that I expect to be worse next year is Northwestern, and it won't be much of a dropoff because they choked so badly in their non-conference games this year.