On 25.b4, there would follow 25...b6, and there is nothing decisive.
Also not very effective is 25.Kf4 Re8 26.Nxe4 b6 – the black bishop comes out to d7, and Black can defend.
Also not very effective is 25.Kf4 Re8 26.Nxe4 b6 – the black bishop comes out to d7, and Black can defend.
25...Kxb6 26.Rxd8 Ka7 27.Nd5 c6 28.Kf4 cxd5 29.Kxe5 d4 30.g5 e3 31.f6 gxf6+ 32.gxf6 1-0