I really don't know that I can truly enjoy the other two routes now that I have played this one.
Not only do I absolutely agree with the path that Edelgard and Hubert set out for their country and continent (change wasn't going to happen without the war/conflict), but the only true villain, in my humble opinion, was The Immaculate One. Dimitri wasn't a villain, but a lost soul who'd experienced much loss in his life. When not having the guidance of someone out for one's best interest (such as Edelgard had in my playthrough with Byleth), but instead a negatively driven person in power, it's clear why it would have ended that way.
Claude never really found who he was within the Black Eagles storyline. While I picked Edelgard at the beginning, Claude was my second choice (sorry Dimitri). His demeanor is just so radically different from the other two that he really is his own man. The other two House Leaders have an intertwined fate, as it were. Considering the fact that I spared him in my playthrough (as there was nothing to be gained from killing him), I would absolutely be interested in a potential storyline of Claude post-defeat, and a story in which he finds himself, potentially in a new land.
While I have not played the other routes (I'm not sure when I will, but my stamina is not quite there just yet...plus I'm just loving the playthrough I just had), I have to say that this particular route just...feels like a canon Fire Emblem story. The true "evil" of Fodlan is the sphere of influence the Church of Seiros claims over the inhabitants. Geralt warns you (at least in the Black Eagles route) to not entirely trust Rhea, and Rhea is extremely vicious with her tactics in eliminating those who oppose the church. This is particularly evident when she tells Byleth that she "wants the students to know what becomes of non-believers", or at least people who attempt to rise up against the church. As long as that sort of power lingers, people wouldn't be able to live a life without fear.
Not to mention, a common story of JRPGs is typically to...rebel against the gods and take back decision-making power in human existence. Xenoblade comes to mind especially as a comparable story. Not that that means anything.
I feel deeply for Dimitri, and Dedue. I feel for Catherine. Though, the game sets it up so that you do feel bad. None of those killings felt good to me. Incidentally, I was at a crossroads during the final boss as to whether or not to kill Catherine, but based on how I structured my troops I was forced to. After defeating her, I took the Thunderbrand and equipped it on Felix. BRUH. HE'S A GOD. The only reason I took down Rhea within two turns of reaching her was because of that and...grinding. Byleth ended up level 46, with pretty much every other unit being over level 40 by the end of the level.
It also took me...two hours.
I'm not sure that Edelgard outranks Ike as my favorite lord, but she's close. This game is far better than Fates based on this route alone, and I imagine the other routes are excellent. The characters are well written, provoke emotional intrigue by the player, and well...the structure of the game is absolutely perfect. Whether they expand on the monastery and make it a town/city, or different locations throughout a game, or an army camp, they should absolutely continue it. I felt a much stronger attachment to the units in this game than probably any other Fire Emblem I've ever played.