1. Need More Space
   Growing family, working from home, hobbies, pets, or just feeling cramped.
2. Desire to Build Equity
   Buyers often want their monthly payment going toward something they own instead of rent.
3. Life Changes
   Marriage, divorce, new baby, retirement, job change, or relocating closer to family.
4. Better Location
   Moving closer to work, school, family, shopping, healthcare, or a preferred neighborhood.
5. Lifestyle Upgrade
   Wanting a bigger yard, garage, better layout, newer home, quieter area, or more privacy.

Simple summary:
People usually buy a home because their current living situation no longer fits their life.