While favicon.ico files were once sufficient for browser tabs, the rise of mobile devices has necessitated high-resolution icons.
While PNG supports transparency, many Android launchers handle transparency poorly. If the OS cannot figure out the background color from your theme color, it will place your icon on a white or black square, looking like a child's sticker. Fill the entire 192x192 canvas. If your logo is a mark (e.g., a bird), put it on a solid brand-color background. icon-192x192.png
The "story" of icon-192x192.png is the evolution of the web from simple static pages to Progressive Web Apps (PWAs) that look and feel like native mobile applications. The Identity of a Web App While favicon
"name": "My Great App", "icons": [ "src": "/images/icon-192x192.png", "sizes": "192x192", "type": "image/png" , "src": "/images/icon-512x512.png", "sizes": "512x512", "type": "image/png" ] Use code with caution. Best Practices for Designing icon-192x192.png Fill the entire 192x192 canvas
You cannot simply resize a logo to 192x192 and call it a day. PWAs have specific requirements.