What is is 28 old?

Whether or not 28 is considered "old" is entirely dependent on the context.

• In terms of lifespan: 28 is generally considered young. Life expectancy in most developed countries is well into the 70s and 80s, making 28 a relatively early stage of adulthood. See: https://www.wikiwhat.page/kavramlar/Lifespan
• In sports: Depending on the sport, 28 could be considered past your prime or approaching it. For physically demanding sports, recovery time and performance may start to decline around this age. See: https://www.wikiwhat.page/kavramlar/Peak%20Performance
• In career: 28 is often a time of career growth and development. Many people are just beginning to establish themselves in their chosen fields. See: https://www.wikiwhat.page/kavramlar/Career%20Development
• In relationships and family: At 28, some people are married with children, while others are single and focusing on other aspects of their lives. There's no "right" age to reach specific relationship milestones. See: https://www.wikiwhat.page/kavramlar/Relationships
• Socially: Social perceptions of age vary widely across cultures and individual viewpoints. What one person considers "old" may be seen as young or middle-aged by someone else. See: https://www.wikiwhat.page/kavramlar/Social%20Perception

Ultimately, 28 is generally considered a young age in the grand scheme of life.