Without military aid Ukraine is obviously the weaker side, so giving military aid does two things: 1) It puts Ukraine in a better position militarily and at negotiating table and 2) If there is no peace deal then it just makes the more longer and more costly by keeping the sides more even.
The policy of giving aid to Ukraine but not pushing for a negotiated peace seems pure evil to me.
Russia started the war and they can end the war by leaving all of Ukraine including Crimea.