I'm not sure what you're describing is really a "limitation" though.
To me, a limitation is to deliberately not use a feature. For instance, when I play Breath of the Wild, I don't heal during battle because I don't like the fact that you can pause the game and heal at any time without penalty. In other words, I'm not using a feature. Using varied classes is a different thing, because when I do that (and I do, got one Wyvern and one Pegasus on my team in my current run), it's not a deliberate decision to limit myself. Instead, it's the result of getting joy out of each character having a different role and playstyle.
In other words, I do understand the OP's problem, and I feel similarly. My favourite parts of any Fire Emblem are often the early game, because that's when I have to rely on limited resources. However, I know that not everyone likes this sort of thing, and having choices in a game is a positive in my eyes. Let those who want to break the game with an army of Wyverns break the game with an army of Wyverns. I personally find that incredibly boring and will never play that way, but to each their own. If that was the ONLY way to play though? That's when we're reaching problem territory.