Coming out of high school, they were very similar, both being praised for being extremely accurate and generally regarded as one of the top quarterbacks in their class. Similar size, skill set. The obvious difference is Tanner is entering a situation where he can learn, grow, and hopefully be fully ready to step on the field.
Jake was growing as a quarterback and playing much better at the end of his freshman year. Last drive of the Utah game was very impressive stuff, until Anae decided to burn clock and kick.
Then the kid gets married, his parents get divorced, and he has to learn a new offense with a brand new coordinator, and lost Unga going into fall camp, so everything is going to be on him. He struggled, they turned to Riley, and the rest is history.
We need to get over burning Jake at the stake. No, he did not pan out, but that's not uncommon for these highly regarded QB recruits. Just look at his Elite Eleven class. Not a single one of the twelve was drafted as a QB. (Blake Bell was drafted as a TE.) Only five of them, including Bell, even made an NFL camp. The most successful guy in that group, Philip Sims, sat for 4 YEARS at Alabama waiting his turn.