First, having low win rates does not neeed to mean that these cards are bad, just that you play them worse than your opponents.
Chapel you gained in 100% of your games. That is probably to much. If there is no great engine to build, and no Curses to defend against, you are often better of ignoring the Chapel, buying money and a few terminals. Copper is not that bad in Province games, taking 3 turns to get rid of it takes time, if you would just buy Silver you would be buying Gold by than. Additionally, you are far more valunable when you green.
If there is an engine to build, Chapel is very very good, but if not, ignore it. Of course low rates on Chapel could also mean that you are not good enough in building engines.
Grand Market is also often a trap in Province games. Without help, a turn you bought a GM could usually have been a turn you bought a Province. Have 2-3 of these turns, and you have a lot to catch up. So Grand Market also needs a reason to be prefered over Provinces. That might be because you can't buy a Province (Vault and Quarry and Chapel gives that situations), or you have a really dense deck which profits from these Grand Markets (Throne Room, King's Court, Srying Pool, maybe Conspirator, Highway). It's not a bad card, it is usually better than Gold, but it's often worse than a Province, unless you have reasons to believe otherwise. Again, you have 85% where you gained the GM, and the games without are about average. So maybe you want just more games without GM.