It’s kinda simple for me.
Progression systems and other stuff that don’t belong in RTS games is what kills them. After the golden age of RTS games they started to over-complicate the formula by adding all kinds of stuff in an effort to further bring innovation just for the sake of it. When they realized RTS games became too complicated for people to bother, they started simplifying them by removing things that were good, instead of the things that were superfluous. For example, removing base building, many of the units, maps and game modes, but keeping the progression systems. So now not only you can’t just jump into an RTS to build a nice base and use all the stuff in the game, but you have to grind over time in some progression system to be able to use everything which is already scarce as a whole.
Well I personally think it’s not case of simple or difficult,
you had your easy C&C, medium Age of Empires and complicated Starcraft
but we had in last years, we kind of had a core shift in the design
-1-the huge change of focus from Macro, to Micro management.
Somehow you have to baby sit your creations, each unit/building is valuable
if you lose today 1 expansion or early some units its game over
in old games you did fast recover and did send another wave of units
You are literally dragged into the combat field, or you will lose.
You can’t be a King behind your walls anymore, turtle and send out units only if you want to
-2-the huge change of focus from base build variation, to combat variation
Somehow you don’t any more build a real base,
its kind of an outpost that does spam some units and you must take points or loose.
And units changed a lot, instead of large armies 40-100 units, you did send out
you have to by 5-10 units to explain them everything,
like where they should stay or what ability they must use
Why does every unit has some kind magic trick you have to activate,
why can’t units have passive abilities any more?
Combat is extremely messy meanwhile and you have to focus on combat, you can’t any more simply build good defences and larger army.
-3-the huge change of focus by AI:
instead of to be a fun script, to be some kind of Multiplayer tutorial teacher
Especially AI is well, how should I describe it? Annoying.
In old days they did simply script AI to attack in waves,
so attack 1, AI did send out after some time 20 units, you kill them,
so you have some time to chill and build till next wave.
Today AI does constantly annoy you with 1 unit attacks, it supposed I guess to simulate a rush ?
So you have to put each early game on same location same tower/units and thats it. The AI never ever even does try to attack you with a wave of units or to attack you from other location.
It gets really fast boring.
So far nobody did even try to make AI at least less annoying and a real challenge.