Note: I realize that Burrow has yet to take an NFL snap and will likely end up on a very bad football team. That said, here are a few reasons why Manziel failed and why Burrow is set to succeed at the NFL level if given adequate time and weapons.

1. Work Ethic

Burrow has demonstrated a willingness to learn new systems. His focus has been on improving his game (as seen in the transition from 2018 to 2019), utilizing his weapons and his coaches.

Manziel did not - seeing more of a regression after his RS Freshman year, as teams adapted but he refused to do so.

2. Staying in the pocket

While QBs who CAN scramble are very productive in the NFL, this cannot be their first instinct. NFL players are faster and better tacklers than even the best collegiate players; moving out of a pocket that has not yet even broken down is a recipe for disaster.

Burrow has demonstrated a willingness to stay in the pocket and continue through his progressions, while Manziel would often break almost immediately once his first read was not there.

3. Over reliance on a single target (or lack thereof)

One of the worst things for Manziel's longevity as a pro prospect was being able to throw to Mike Evans while at A&M. Evans bailed Manziel out of a lot of terrible decisions, including jump balls into triple coverage and sometimes blind throws without being able to adequately see anything that was going on.

Burrow did not pick a single WR and throw blindly to him. Burrow not only spread the wealth among a talented WR corps, but he did not put WRs in a position where they had to be a foot taller than the guy covering them to bail him out. Instead Burrow often led passes to allow for open WRs to stay open, hitting them in stride.

4. The System - A&M's Air Raid vs LSU's RPO

A&M incorporated an Air Raid, and when coupled with Manziel would more often resemble that of backyard football - WRs eventually would break off routes because their QB was already out of the pocket. Manziel rarely had to read defenses because he would throw into the random chaos. This would serve him poorly at the NFL level, as each scramble would lead to getting destroyed by a defensive end or linebacker.

LSU ran an RPO that focused more on the "P" than the "R", and Burrow often would go through a full set of progressions. Burrow did not force his WRs to scramble like chickens during a wolf attack; his calm in the pocket allowed them to run their routes and gave him the opportunity to see those players that were breaking free from their coverage.

5. Nature vs Nurture

Manziel was generating huge numbers before he was 20 years old. Living the party style, he rarely had to work hard compared to others in a similar position - getting away with all sorts of terrible behavior, with no apparent checks or role models.

Burrow grew into his amazing season. Still a gifted athlete, Burrow worked hard and it has shown with a "I'm just blessed to be here" mentality that was clearly on display when he managed to use his podium at the Heisman trophy presentation to generate money for his hometown's food bank.

To sum up:
Manziel was "show ME the money"
Burrow is "show THEM the money, I'm good"

At the end, we don't know if Burrow will be an NFL star, a journeyman, or flame out. I think his prospects look good, especially considering other flaws for Manziel - below average arm strength, height, etc - are not present for Burrow who is the right height and possesses arm strength AT LEAST on par with other NFL QBs.

Two guys who had amazing Heisman winning seasons as QBs while setting a ton of records in the SEC.

Two very different trajectories for them.