I could be the second best QB or second best RB in the nation but if I'm only the second best QB or RB on my team then I'm still not going to get a lot of PT. At WR or DB or OL or DL there are multiple guys on the field every down so if I'm really THAT good then I'll get a chance to show it on the field no matter how good the other guys on my team's roster are.
But that's a conceited high schooler's way to think about it... Because there's talent, and there's physical development/maturity, and there's experience.
If you're a 5* coming into a school where you're surrounded by other 5* players at your position, you have the talent but you don't have the physical development or the experience. So if talent is equal, you're still behind them.
Now, that situation won't last forever. You might get on the field eventually as the guys older than you move on. But you're going to have a tough time coming in as a freshman and competing for PT against guys equally talented but who have the other aspects.
George Karlaftis (#59 nationally according to 247) was the top recruit at Purdue in 2019 as a high 4*. He would have been the 4th-best recruit at OSU, and 2nd-best at his own position (DE). On top of the fact that he already had Chase Young there, the other DE (Zach Harrison) was the 12-best recruit in the country. He wouldn't have seen the field IMHO. At Purdue, he led the team in sacks, TFL, and was 3rd in tackles/game.
David Bell (#113 nationally) was the 2nd-highest ranked recruit at Purdue in 2019. He would actually have been the 5th-best recruit at OSU, but only the 3rd-best at his own position (WR). Ahead of him were Garrett Wilson (#20 nationally, 2.1 rec/game) and Jameson Williams (#82 nationally, 0.5 rec/game). Bell led Purdue in rec/game (7.2), amassed over 1000 receiving yards, and won Big Ten Freshman of the Year.
It's one thing to go into a competitive atmosphere and believe you're got a chance to compete for PT against the best in the country. It's another to know that you can walk on a team and as long as you put the work in, you're going to be a superstar for that team.