The UUs in AoE2 are “archer but faster”, “knight but stronger”, “champion but has more armor”.
The UUs in AoE3 are “musketeer, but has 5 different stances with different stats, multipliers and use cases”, “skirmisher, but fires twice as fast, has longer range, and sieges buildings from a distance at the cost of hit and run capabilities”, “dragoon, but actually also heavy cavalry and counters heavy infantry too”.
I mean, AoE2 is great and all, but the UUs mostly feel like stronger reskins. The game is dated. Everyone who thinks AoE2 would be praised for complexity if it was released in 2022 is dead wrong and living in some fairy tale universe.
Asymmetric civs is nice, AoE4’s approach was completely flopped though and crashed and burned immediately due to incompetence. Still, considering out of 42 civs here in 1 on 1 you can play 35 of them with the same archers into crossbows (for 30 minutes, most games have ended by then), another selection of 25 on scouts into knights, and it’s 2 unit lines that dominate the meta on all levels and they are all we see, I don’t think one can put out any solid argument for civs having “flavor” in AoE2.
When I play Persians I play Franks. And Lithuanians. And Sicilians. And Teutons. And Burgundians. And Poles. And Burmese. And Khmer. And Malians. And I haven’t even changed my civ.
Because Civs in AoE2 play out exactly the same for the first 45 minutes of the game, or in other words, in 90% of games. Every time, over and over.
Oh, and for “b-but if people agreed with you AoE2 wouldn’t be the most popular”.
AoE2 is popular because of the much better campaign approach compared to both AoE3 and AoE4, because of the more sim-city style of spending the first 15 mins building and designing your base, and because of the more defensive, passive and slow-paced approach it uses. Not because the civilizations are fun to play. The replayability is ensured by the maps, the engine, and the action, not by the units, civilizations and balance.
And why not have even more replayability?