Gee, less than a thousand really makes a huge difference, especially as students aren't even on campus.
No one is saying that NU has a big fan base, much less season ticket holders (usually average around 12-15k), but that's been the case for over a century and when the program hasn't been hamstrung by the admin (like for during the "Dark Ages"), they've been competitive enough.
Since 1995, the Cats have done better than the majority of B1G programs that aren't dOSU, UM, PSU, UW and Iowa (and with the latter 2, have around a .500 record).
Does this mean that they will be in the running for the national championship? no
Or even a B1G championship? Probably not, but wouldn't be surprised to see them make some noise every 4-5 years with an upperclass-laden team.
Once the new stadium is finished, the big donors will switch their focus to NIL.
Now, due to academic restrictions (which, btw, Dook does not have), will continue to have certain limitations when it comes to recruiting and the transfer portal, but most of us are fine with that.