Does anyone else find Elincia underwhelming?

Well if you expect a good defense phase from a Brave user you're doing something wrong. Brave weapon wielders always only shine on the player phase. That's why you're giving her hit and run so that she can safely kill/severely injure the enemys

Give her more support. Other fliers with reposition, a dancer, fortify/hone flies, etc. She's definitely a glass cannon but you can play around that.

She is definitely not underwhelming. She is a top player phase unit. I mean, Reinhardt, Cordelia and Brave Lyn are easy to kill, too. They are just really really strong in player phase.

If you do a quick matchup simulation, Elincia can kill 130+ units with her default set. Not many units can do that even with heavy SI. -Spd hurts her, but with just a hone attack buff she gets to 145 wins. I know that these numbers are not accurate at all because you face merged units in arena with fury3 and stuff, but it gives you a broad idea of how good an unit can be.

The fact that she ignores terrain makes her easy to reposition and handle. In flier emblem she is godly. Even outside of a flier emblem team she is a top red unit.

"Squishy" they said. "Underwhelming", they added.

No, I do not think Elincia is bad in any objective measure. Her raw offensive potential surpasses even the likes of Cordelia due to the effective +3 atk/spd on her weapon, and she can be buffed into divinity. The -spd does hurt, but +atk Deathblow is still extremely effective on player phase.

That's like saying Bridal Cordelia shouldn't be 5/5 because she sucks on Enemy phase.

She is Hana with +2 attack and +3 speed. And flier movement. And +1 in both Defense and Resistance. And access to flier buffs. And a legendary weapon.

Hana is an amazing attacker, worthy of 5*.

One plus one adds up to three, in this case, my friend.

Your problem is that she's -SPD. Give her +SPD, and she'll be rocking 37 SPD. 40 with Fury. That's enough to quad all but THE fastest units in the game, and a few specifically specced for SPD (like other quad users, who are oftentimes very squishy).

She is a brave (Aimiti technically a legendary brave sword) weapon user, meaning they are only strong during player phase and not meant to take hits. You should not even be letting her get hit as she is so squishy, she will get killed even by high atk axe users when they counter attack (if she didn't kill).

All brave weapon users share the same weakness of being very weak during enemy phase, so you should not compare her to non brave users (Shes no Ryoma / Ike / Black knight after all).