Every Fire Emblem has a "beginner's trap" character. You use Fredrick a lot and you'll find yourself woefully under-leveled
Okay so this is one of those topics that I can talk for ridiculous lengths about lol.
STRAP IN, EVERYONE. OPOSSUM'S GONNA TALK ABOUT JAGEN UNITS!
In all honesty, the belief that Jagen-styled units are a beginner trap is, in itself, a beginner trap. By definition, a "Jagen" unit is the prepromoted unit you get toward the beginning of the game that has base stats far exceeding the other units, but lower growth rates. Generally, story-wise, these are characters with more experience in combat than the main lord and their compatriots. A veteran. But not always. For a relatively complete list:
Shadow Dragon and the Blade of Light/Mystery of the Emblem Book 1/Shadow Dragon: Jagen
Mystery of the Emblem Book 2/New Mystery of the Emblem: Arran
Genealogy of the Holy War: Oifey
Thracia 776: Dagdar
The Binding Blade: Marcus
The Blazing Blade: Also Marcus
The Sacred Stones: Seth
Path of Radiance: Titania
Radiant Dawn: Sothe
Awakening: Frederick
Fates: Gunther
That's the generally-accepted list. Of note, with the exception of Sothe and Dagdar, all of these are either paladins or great knights, horseback units. As well, Gaiden/Shadows of Valentia is the only game without a Jagen, mainly because funny enough, the Lightning Sword is the closest the game has to a Jagen, but it's a weapon and not a unit. The game does a fake-out, making players believe that Mycen will be the game's Jagen (as he fits the story role for the archetype), but the game subverts this and has Mycen be the final recruitable character.
The common misconception is that Jagen units fall off the wagon after a certain point, when oftentimes this isn't the case...not even with Jagen himself, which is where my main issue with this stance comes from. It's also why I don't agree that Oifey is worthy of being its own classification of unit archetype...mainly because Jagen himself is more vital to FE1/3b1/11 than Oifey is to FE4, so the distinction is rather meaningless. Yeah, Seth is on a level above everyone else, but Seth is one of the best units in the franchise in general, being able to literally solo FE8.
The main thing that makes the "Jagen units suck after a few chapters" line of logic fall apart is the fact that without them, 0% Growth runs would be literally impossible. And yet, the only game and difficulty in the series that hasn't been beaten on 0% Growth is Awakening's Lunatic+ mode. But because games can be hacked to give 0% growths to everyone and the game is still very much beatable, it shows that these units are not nearly as much of "noob traps" as some people believe. Frederick is absolutely vital for Awakening's early game on Hard Mode and absolutely
mandatory on Lunatic (it's called Frederick Emblem for a reason). Titania is a standout unit throughout Path of Radiance. Jagen
himself is incredibly useful throughout all three of the games he is playable in, but especially in FE1 and FE11. In the former, stat boosting items work very differently than in the rest of the series, so giving a few to Jagen makes his stats exponentially higher than they need to be, and in the latter, forged weapons and his high weapon rank let him deal ludicrous amounts of damage even if his strength starts to falter, making him more than capable of making it to the endgame without much babying. And "exp thieving" isn't really a thing unless you're doing an extremely specific speedrun or LTC.
So where did this belief come from?
Well, to say there was a values shift among Fire Emblem players over the years is an understatement. Early on in the fandom's life, growth rates were valued immensely while base stats were somewhat ignored. However, in more recent times, base stats have come back into vogue. I've always been a staunch believer of Bases being better than Growths.
When you have a unit with good base stats, you have a failsafe. Those base stats are a unit's only guaranteed stats, outside of literally 100% growths. With a unit that relies on growths, especially Est-styled units like Est and Nino, or trainee units like Amelia and Donnel, while their growth rates are high, they're not guaranteed. A bad level up on a unit with good base stats isn't the end of the world, as they still have their base stats to fall back on. But a bad level up on a high growth, low base stat unit? It very well could be detrimental. Add onto that that you need to feed these units extra kills instead of just taking enemies out with your stronger units, and it just makes the game harder. I'm also of the opinion that the reward doesn't match the cost either. You use a deployment slot for a unit that cannot pull their own weight yet, in the hopes that, with enough babying, they eventually
will be able to, but it's a gamble...and then they'll likely not even be that much better than your other units by endgame. It's why I'm a firm believer that, from a gameplay perspective, Pent is better than Nino like, 9.8 times out of 10, to give an example. It's also why Palla is considered among the best units in every game she's playable in while Est ranks toward the bottom. The one exception I can think of is Delthea, but that's because she eliminates some of the key drawbacks that Est-styled units have: Gaiden and SoV have unlimited deployment outside of dungeons, and the chapters immediately after her recruitment are swarming with low-resistance enemies. Because of that, there isn't a reason not to use Delthea at least somewhat.
So that's basically my take on things. In other words...
"
Do not turn your back on me!"