While it is true that tire liners can add a small amount of rolling resistance to a bike, the difference is so miniscule that it is unlikely to be noticed by most cyclists. In fact, the primary reason for using tire liners is not to reduce rolling resistance, but to prevent punctures. The thick material of the liner protects the inner tube from sharp objects on the road, and in some cases can even seal small holes if they do occur. So while they may slightly increase your bike's rolling resistance, tire liners are well worth it for the peace of mind they provide.