Why do tennis players change ends during a match?

Answer: It makes both players face the same sun and wind during the match

It makes both players face the same sun and wind during the match ✓ — Correct. On many courts one end has the sun in a player's eyes and the wind at their back or in their face. Players change ends after odd-numbered games, so each player serves and receives from both ends. Over the match, both players deal with the same glare and the same wind, so the conditions do not favor one side.

It stops one player from overworking the same muscles all match — Wrong. Switching ends does not change which muscles a player uses, because the strokes and footwork are the same at either end. The switch is about the sun and wind around the court, not about resting one side of the body.

It gives players a chance to check the court surface for damage — Wrong. Players switch after odd-numbered games so both sides face the same conditions, not to inspect the court. Someone might glance at the surface during the break, but checking for damage is not why the rule exists. The switch is set by the game count, not by a grounds check.