There are a few reasons why Google Bard is only available in the US and the UK (which is why you’ll need a top-quality VPN to access the service when you travel abroad):
Regulations — different countries have different regulations surrounding AI, so Google must make sure all necessary requirements are met before launching Bard.
Localization — Google Bard is still under development, and Google is working hard to localize the service for other countries, to ensure Bard can understand prompts and generate responses in multiple languages and cultures.
Service demand — Google wants to make sure that demand for Bard is high enough in other countries before releasing it worldwide.