Recruiting rankings have historically been pretty predictive of on-field success. Pay-for-play and the portal may or may not have severed that connection....there hasn't been enough time to know yet.
Pre-portal, the analogy I used to draw was ACT score vs. collegiate grades.
We all know kids who made 32 on the ACT, got distracted by whatever outside influence, didn't go to class or study, and flunked out of school. We also know kids who made 23, busted it every day even when everybody else was out having fun, and made Phi Beta Kappa.
Human nature is that we like to remember the outliers and think those happen "all the time." They don't. That's why they're called "outliers," in the first place.
What we overlook is the significant majority of kids that performed in a manner that surprised nobody -- made 32 and graduated with honors, or made 23 and struggled to get a gentleman's C.
Predicting human performance at the individual level is tough. Some 5 stars don't pan out. Some unrated players make All-Conference. But when the law of large numbers kicks in, that changes. Or it used to anyway.
To illustrate on the academic side: Give me a roomful of kids who scored 32, and our academic performance will run circles around a roomful who made 23.
Similarly, before the portal, give me a class full of 4 and 5 stars and we'd consistently beat a class full of unrated to 3 star players -- acknowledging that there will be outlying performances both ways (like Albano and Arenas noted above).
With the portal, you now have blue-chip prospects that don't play as freshmen or get offered more money and transfer out. How do you rate them at the new school? Are they still blue-chips? Or are they of undetermined quality? I don't know.
It will take time to evaluate how 4 and 5 star players who transfer perform at the new school vs. 4 and 5 star players who don't transfer.