dow3 have some problems but it can be solved
dow1 and dow2 were also bad games at first, but they became good games through dlc
dow3 was an experimental challenge during the decline of RTS and was undervalued
Why should relic make it similar to a game with fewer than 500 concurrent users?
Would you really be if you were a game developer?
The biggest problem with dow3 is that Relic abandoned the game too soon for AOE4
DoW and CoH would have been never been so critically acclaimed and spawned games after them if they were as bad as DoW3 when they first came out, and yes I know they weren't so bad, or CoH at least since I played it back in 2006.
DoW3 just came out dead even after people warned and told Relic to not keep the mechanics that were being identified as troublesome but they preferred not to listen and thus doomed their game, they had ample time to make the changes to the cover system, hero units and so forth.
I can't comment on either DoW or DoW2 as I didn't played them on their release.
DoW3 in my opinion was just a badly designed attempt at a cash grab from MOBA playing children but they also included RTS elements in order to appease their fan base so it was basically a compromise, a bad one at that.
It's still possible to fix the game through some sort of DLC or huge, game fixing update, similar to what the No Man's Sky devs did, but it will take a lot of time, effort and resources as well as manpower, obviously, and I don't think Relic want/can do that right now but I hope they come back to it and fix the game one day, even if it's after AoE4 or something.