What features make Google Data Studio a popular choice for data visualization?

Data visualization including:

• Ease of use: You can create reports in minutes by connecting to data sources, adding data, and formatting it. 
• Customization: You can customize the font, color palette, text size, border color, background, and alignment of your graphs and tables. 
• Real-time data processing: You can create interactive dashboards in real time. 
• Integration with multiple data sources: You can connect to up to 12 different sources, including Google Analytics, Google Sheets, and Google Ads. 
• Report sharing: You can easily share reports with team members and customize user access. 
• No licenses or downloads: Google Data Studio is free and available online, so you don't need to download anything. 
• New features: New features and bug fixes are released a few times each month, including conditional formatting, pivot tables, and dashboard themes.

Other benefits of Google Data Studio include:

• Enhanced data collaboration
• Ability to create comprehensive, visually appealing reports
• Simple reporting
• Effective campaign monitoring
• Reduced turnaround time on reporting 

Google Data Studio or Looker Studio is not the ideal choice for me.

Why it can be a popular choice?

1. People wanting to stay within the Google environment.

2. Easy to do basic charts. Easy to do big things. (As soon as you start asking small questions or looking for deep analysis, it won't support you)

Power Bi is the best tool there is. Tableau has popularity but I think its a legacy software which captured the market in its early days.