Q.In real life objects, never travel with uniform velocity, even on a horizontal surface, unless something is done? Why is it so? What is to be done?

[!TLDR] Real surfaces always exert friction (and air exerts drag), which are unbalanced opposing forces that decelerate any moving object unless an extra force is continuously applied to exactly cancel them. [!ANSWER] Friction/drag must be overcome by an equal continuous applied force for uniform velocity to be maintained in real life.

In an idealised, friction-free and drag-free world, Newton's first law says a body set into motion would continue at constant velocity forever with zero applied force. In the REAL world, however, every horizontal surface exerts some frictional resistance on a sliding object, and every object moving through air experiences some viscous drag -- both are genuine, unbalanced opposing forces (per Newton's second law) that decelerate the object over time. For the object to maintain a truly constant (uniform) velocity in real life, an additional applied force must be supplied CONTINUOUSLY, exactly equal and opposite to the friction/drag, so that the NET force remains zero. This does not contradict Newton's first law; it simply confirms it -- 'no net force' (not 'no forces at all') is the true condition for unaccelerated motion, exactly as clarified when correcting Aristotle's Fallacy (4.2). [!ANSWER] Friction and air resistance are always present in real life; a continuously applied force exactly equal and opposite to these resistive forces must be supplied to keep the NET force zero and thereby maintain uniform velocity.

Apply Newton's first/second law correctly: uniform velocity requires zero NET force, and since real surfaces/air always supply some resistive force, an equal counteracting applied force is needed.

Repeating Aristotle's original (incorrect) claim that force is needed to sustain ANY motion, rather than correctly stating that force is needed only to counteract the always-present resistive forces in real life.