I was thinking a lot about Fire Emblem's gameplay as a whole, and ultimately came to a few conclusions about the difficulty. In most Fire Emblem games, the game is relatively difficult at the beginning, as all of your units are rather weak, and you're getting introduced into the game.
The game begins to lessen the hold on the player with the difficulty as it goes on, growing alongside all of your units. However, eventually your units just straight up outpace the enemies in terms of pretty much everything, to the point where things taper off to a really easy difficulty at the end.
While this is great for feeling as though your units are becoming stronger, and more able to overcome obstacles, the game's difficulty suffers as a whole, being really easy near the end. I feel like the way Fire Emblem games should be designed near end game is through not just higher power enemies, but rather through smarter enemies.
You should be able to still have your units wipe the floor with generic Paladin #121827, but try to fuck with that Paladin, suddenly you're overwhelmed with a situation you really need to make a gamble with. Or something like that. Point is, I think Fire Emblem games are kind of easy (with the exception of you, FE10) but can be like way better lol