The whole "develop" model that UW was successful with is dead, and for several reasons.
It's much harder to find "hidden gems". There's so much more high quality video available on kids now versus ten years ago. From games, from camps, social media. Kids are putting out their own video and tagging coaches, recruiters, columnists for recruiting rating services. The "overlooked" kids now are few and far between.
The portal - if a kid feels like they should be starting and they aren't, they hit the portal. (See: Nolan Rucci - he didn't want to sit behind Nelson and Mahlman for another year, so he left). And pretty much every kid who is being recruited by a top school thinks they should be starting (key word - "thinks").
Poaching by schools with bigger NIL funds. (See: Xavier Lucas) If a kid does show something, other schools with bigger budgets come sniffing around. (Or the kid starts putting himself up for auction - I know for a fact that back as early as January agents for kids were reaching out to Greg Gard telling him that if UW was interested their kid would hit the portal after the season was over. There's a ton of that going on.) Some schools have eliminated public access to practices to try to stop "scouts' for other schools from seeing who looks good in practice.
Potential walk-ons are taking scholarships elsewhere due to cost of school. With the state of WI funding less and less of tuition and costs at UW, the cost of attending UW has skyrocketed. That, coupled with inflation and the cost of everything going up (housing, vehicles, vehicle insurance - do you know how much it costs to insure a teenager now?) has made it much more financially hard to walk on when they can get scholarships or partial scholarships at a Northern Illinois, Central Michigan, South Dakota State, etc. And, going back to #2 and #3, they think that if they can start earlier at a smaller school and show something then they'll get offered something in the portal. And they usually do.
We cannot compare anything of the sport/business of college football today to pre-2020. It's just a completely different landscape, and much of the way things were pre-2020 is dead now.