I won#t say its a bad combat system, but one, which lacks seriously depth and character development complexity to make usage of all of its potential that the Combat System could have provided for TW3 to make the Combat System much more fun and interesting.
The Combat System of TW3 is an absolute unbalanced mess, thats why people are saying its bad.
I've played through the Game on its hardest difficulty, Death March, and it hardly felt challenging at all.
How should a Game like TW3 be challenging, when you can permanently evade all attacks??
The only real challenging battles you have in this game with DM begin in the xpansion Content, there you finally start to see a serious change in the difficulty of the battles due to better A.I.s of the enemies and abilities of them, that make the combats more challengign and fun, that you seriously need to use also Decoctions and Potions, where in the vanilla game you could theoretically play it through in DM without using anythign at all, it still feels like an optionality for you, that you can use them if you want, to make things be done a bit quicke,r but neccessary to use the stuff you have? No.
But then come to get your first fights in DM B&W against a biug crowd of Giant Worms or Archespores or better a large Crowd of Kikimores, and you will be surprised, how you wil lget your ass kicked, if you dont use there all your abilities you can to survive in DM, becuase there these beasts all hit hard like trucks and can quickly kill you, if you dont use defensive decoctions ect .
This heavy unbalance is it, which makes for sure many people say, that this games combat system is bad, and in regard of the character developüment I can only agree to this....the combat system and large parts of the character development absolutely feel like, as if these areas of the game have seen the least love of the developer,s because it seems to be, that it was oen of the last thigns they worked on and run out of budget money to put more quality and content into it, to make the whole package aroudn these systems more complex and interestign to make usage of its potentials, because CDPR focused all their budget mainly on the world creation ,quests, voice actors, animations ect. and combat/charatcer developmetn god basically the short end of the stick.
Thats how i do see it now after playing through the game and being in B&W, having seen by now all gameplay mechanics and how they work together to get by now a complete picture of the games gameplay construction and how the mechanics work together.
Stuff like decoctions, monster drophies, runes and glphy seem to be all some kind of afterthought, which got basically added at the end of the game, because some dev seemd to have thought it would be nice to have these things in the game, but then they didn't put very much thought into the design of these things, which you can clearly see at the Trophies, where alot of them share the same more or less useless effects that make up for absolutely no difference, where they could have put into the game alot mroe useful and interestign effects, that you clearly can see in the combat having their effects, when you use them, so that huntign al kinds of monster trophies actually MAKES SENSE to increase this way your build diversity and give you more abilities and options how you can engage into combat and how you could profit from using all kinds of various monster trophies...
They even made it so far not possible to use the trophies as decorations to hang them onto walls in our own mansion in B&W Corvo Bianco, where we coudl hang them up like portraits on the walls, like that cat school witcher which collected trophies to hang them out in his hidehout for show.
Once you have played through the whole game basicaly you start to realize in so many thigns and places in this game, where CDPR has wasted alot of good potential to make this game even much better, than it already is xD.
The game has an epic story, awesome voice actors which give their charactrs really prsonality, a wonderful game world to xplore, but it still feels due to the lack of making usage of all its potentials it so empty. Best example for this is Skellige Island, or how I do call it by now.... Siren Orgy Islands, because once you're there, you will mostly see nothign else than 95% of all your tiem, than half nude sirens flying around you or their half nude step sisters, the Echidnas....(very creative *rolleyes*)