If you mean products like cigarettes or cannabis in some places, it's because laws often require standardized or "plain" packaging to reduce the product's appeal and make health warnings more noticeable.
The reasoning varies by product and jurisdiction, but common goals include:
- Reducing marketing influence. Companies use colors, logos, and package design to make products more attractive and build brand recognition. Plain packaging limits those marketing tools.
- Increasing the visibility of warnings. Large health warnings and graphic images stand out more when they aren't competing with colorful branding.
- Reducing appeal to young people. Public health authorities argue that standardized packaging makes these products less attractive to people who have not yet started using them.
- Making products easier to identify. Uniform packaging can make required information, such as ingredients, potency, or health warnings, easier to find.
For example, several countries require plain packaging for tobacco products, while many places with legal cannabis require child-resistant, opaque, and minimally branded packaging. These rules are generally intended to balance legal sales with public health and safety concerns.
If, instead, you meant all legally sold products in general, that's not the case. Most consumer goods—from food to electronics to clothing—are free to use distinctive branding, subject to regulations about truthful labeling, safety information, and consumer protection. Only certain categories, especially products associated with significant health risks or safety concerns, are subject to unusually strict packaging rules.
