Acceptable, with room for improvement. It's all very well to go to the gym, but you need to change your diet too if you want to improve your overall health.
All right or quite true as far as it goes. For example, It's all very well for Jane to drop out, but how will we find enough women to make up a team? This idiom, first recorded in 1853, generally precedes a question beginning with "but," as in the example. Also see well and good.