AOE3 has several good innovations for this franchise. Mercenaries, Metropolis, Home City Cards, Saloon, Explorer, Treasure, Manned siege units, Minor civilizations, Consulate and anothers.
I dont talking about for copy all but adapt and implements with balanced and good mechanics for game. Dont need discard all because nothing. Make aoe2+aoe3 all inovations in game.
I think it comes down to these two reasons, one of them is that AoE3 is not as popular as AoE2 and AoE4 is more similar to it than AoE3 and the second reason would be that some of these features that stand out for AoE3 doesn’t exactly fit what AoE4 is and the timeline and therefore wouldn’t make any sense in that regard.
Just adapt and modify for work good but discard is bad ideia.
Do you mean that before the modern age there were no tribes, or mercenaries, or supply chains? The mechanics of AOE-3 can be adapted to any period of history.
Will there be mercenaries and minor factions?
Possible mercenaries
<Mercenaries and minor factions> Mechanics that should not be discarded. The best of AOE-3 for me!
That might be true in some regards but my other point still stands it wasn’t touched as AoE3 is less popular in the big context compared to AoE2 and it’s easy to see which direction they took ideas from while making AoE4.
Devily may cry reboot is not popular but all mechanics reused in DMC5
Yes, maybe the reason is that they were highlighted because it is less popular, which is very unfair.
We’re talking about AoE4 now and not Devil may cry reboot.
I’m pretty sure that they at least considered taking some features from AoE3 when they still were making AoE4 but for many reasons they chose a different path. Who knows what future DLC/Expansions might bring to AoE4 so never say never, might happen at some point in some capacity.
Well, it took almost 1 year for game leave early acess state 
Mmm I agree with the AOElll is not that popular but the reason for this is not the gameplay I think is the time period, medieval time is a lot more popular/fun that using rifles, and the trading card system is not that great IMO but everything else I think AGE lll is superior game.
Card System can be reworkd for make unique game style based in offensive, defensive or in economy,
Yes AOE4 should be more innovative like AOE3. Besides placing units on walls there are no new features compared to previous AOE titles. Sadly placing units on walls is not really useful because of the weak stone walls.
I hope AOE4 will have Minor civilizations, Natives, Explorer, Treasures, an AI with character like AOE3 (very important) and lots of other innovations.